问答

1答疑

[Sentence Correction]

登录查看答疑

试题详情

题目：

While studying the genetic makeup of corn, a new class of mutant genes was discovered by Barbara McClintock, a discovery which led to greater understanding of cell differentiation.

选项:

A、a new class of mutant genes was discovered by Barbara McClintock, a discovery which led
B、a new class of mutant genes in corn were discovered by Barbara McClintock, leading
C、Barbara McClintock discovered a new class of mutant genes, and it led
D、Barbara McClintock discovered a new class of mutant genes, a discovery that led
E、Barbara McClintock, who discovered a new class of mutant genes, leading

答案:

D
1答疑

[Sentence Correction]

登录查看答疑

试题详情

题目：

Recently discovered fossil remains strongly suggest that the Australian egg-laying mammals of today are a branch of the main stem of mammalian evolution rather than developing independently from a common ancestor of mammals more than 220 million years ago.

选项:

A、rather than developing independently fromrather than a type that developed independently from
B、rather than a type whose development was independent of
C、instead of developing independently from
D、instead of a development that was independent of

答案:

B
1答疑

[Reading Comprehension]

登录查看答疑

试题详情

文章：

Line        In the Sonoran Desert of northwestern Mexico and
 southern Arizona, the flowers of several species of
 columnar cacti—cardon, saguaro, and organ
 pipe—were once exclusively pollinated at night by
(5)nectar-feeding bats, as their close relatives in arid
 tropical regions of southern Mexico still are. In these
 tropical regions, diurnal (daytime) visitors to columnar
 cactus flowers are ineffective pollinators because,
 by sunrise, the flowers' stigmas become unreceptive
(10)or the flowers close. Yet the flowers of the Sonoran
 Desert cacti have evolved to remain open after sunrise,
 allowing pollination by such diurnal visitors as bees and
 birds. Why have these cacti expanded their range of
 pollinators by remaining open and receptive in daylight?
(15)     This development at the northernmost range of
 columnar cacti may be due to a yearly variation in the
 abundance—and hence the reliability—of migratory
 nectar-feeding bats. Pollinators can be unreliable
 for several reasons. They can be dietary generalists
(20)whose fidelity to a particular species depends on
 the availability of alternative food sources. Or, they
 can be dietary specialists, but their abundance may
 vary widely from year to year, resulting in variable
 pollination of their preferred food species. Finally, they
(25)may be dietary specialists, but their abundance may
 be chronically low relative to the availability of flowers.
      Recent data reveals that during spring in the
 Sonoran Desert, the nectar-feeding bats are
 specialists feeding on cardon, saguaro, and
(30)organpipe flowers. However, whereas cactus-flower
 abundance tends to be high during spring, bat
 population densities tend to be low except near
 maternity roosts. Moreover, in spring, diurnal cactus-
 pollinating birds are significantly more abundant in
(35)this region than are the nocturnal bats. Thus, with bats
 being unreliable cactus-flower pollinators, and daytime
 pollinators more abundant and therefore more reliable,
 selection favors the cactus flowers with traits that
 increase their range of pollinators. While data suggest
(40)that population densities of nectar-feeding bats are
 also low in tropical areas of southern Mexico, where
 bats are the exclusive pollinators of many species
 of columnar cacti, cactus-flower density and bat
 population density appear to be much more evenly
(45)balanced there: compared with the Sonoran Desert's
 cardon and saguaro, columnar cacti in southern Mexico
 produce far fewer flowers per night. Accordingly,
 despite their low population density, bats are able to
 pollinate nearly 100 percent of the available flowers.

题目：

According to the passage, which of the following types of nectar-feeding pollinators is likely to be an unreliable pollinator of a particular cactus flower?

选项:

A、the lease-loan buyer is not required to make
B、with lease-loan buying there is no requirement of
C、lease-loan buyers are not required to make
D、for the lease-loan buyer there is no requirement of
E、a lease-loan does not require the buyer to make

答案:

B
1答疑

[Sentence Correction]

登录查看答疑

试题详情

题目：

Although a number of excellent studies narrate the development of domestic technology and its impact on housewifery, these works do not discuss the contributions of the women employed by manufacturers and utility companies as product demonstrators and publicists, who initially promoted new and unfamiliar technology to female consumers.

选项:

答案:

A
1答疑

[Critical Reasoning]

登录查看答疑

试题详情

题目：

Although the discount stores in Goreville’s central shopping district are expected to close within five years as a result of competition from a SpendLess discount department store that just opened, those locations will not stay vacant for long. In the five years since the opening of Colson’s, a nondiscount department store, a new store has opened at the location of every store in the shopping district that closed because it could not compete with Colson’s.

Which of the following, if true, most seriously weakens the argument?

选项:

A、Many customers of Colson’s are expected to do less shopping there than they did before the SpendLess store opened.
B、Increasingly, the stores that have opened in the central shopping district since Colson’s opened have been discount stores.
C、At present, the central shopping district has as many stores operating in it as it ever had.
D、Over the course of the next five years, it is expected that Goreville’s population will grow at a faster rate than it has for the past several decades.
E、Many stores in the central shopping district sell types of merchandise that are not available at either SpendLess or Colson’s.

答案:

B
1答疑

[Sentence Correction]

登录查看答疑

试题详情

题目：

If Dr.Wade was right, any apparent connection of the eating of highly processed foods and excelling at sports is purely coincidental.

选项:

A、If Dr.Wade was right, any apparent connection of the eating ofShould Dr.Wade be right, any apparent connection of eating
B、If DL Wade Is right, any connection that is apparent between eating of
C、If Dr.Wade is right, any apparent connection between eating
D、Should Dr.Wade have been right, any connection apparent between eating

答案:

D
1答疑

[Critical Reasoning]

登录查看答疑

试题详情

题目：

To protect certain fledgling industries, the government of country Z banned imports of the types of products those industries were starting to make. As a direct result, the cost of those products to the buyers, several export-dependent industries in Z, went up, sharply limiting the ability of those industries to compete effectively in their export markets.
Which of the following can be most properly inferred from the passage about the products whose importation was banned?

选项:

A、Those products had been cheaper to import than they were to make within country Z's fledgling industries.
B、Those products were the ones that country Z was hoping to export in its turn, once the fledgling industries matured.
C、Those products used to be imported from just those countries to which country Z's exports went. 
D、Those products had become more and more expensive to import, which resulted in a foreign trade deficit just before the ban.
E、Those products used to be imported in very small quantities, but they were essential to country Z's economy.

答案:

A
1答疑

[Sentence Correction]

登录查看答疑

试题详情

题目：

Around 1900, fishermen in the Chesapeake Bay area landed more than seventeen million pounds of shad in a single year, but by 1920, overfishing and the proliferation of milldams and culverts that have blocked shad migrations up their spawning streams had reduced landings to less than four million pounds.

选项:

答案:

B
1答疑

[Sentence Correction]

登录查看答疑

试题详情

题目：

Hundreds of species of fish generate and discharge electric currents, in bursts or as steady electric fields around their bodies, using their power either to find and attack prey, to defend themselves, or also for communicating and navigating.

选项:

A、 either to find and attack prey, to defend themselves, or also for communicating and navigating
B、 either for finding and attacking prey, defend themselves, or for communication and navigation
C、 to find and attack prey, for defense, or communication and navigation
D、 for finding and attacking prey, to defend themselves, or also for communication and navigation
E、 to find and attack prey, to defend themselves, or to communicate and navigate

答案:

E
1答疑

[Problem Solving]

登录查看答疑

试题详情

题目：

Of the 3,600 employees of Company X, 1/3are clerical. If the clerical staff were to be reduced by 1/3, what percent of the total number of the remaining employees would then be clerical?

选项:

A、25% 
B、22.2% 
C、20% 
D、12.5% 
E、11.1%

答案:

A
0评分
363浏览

[Undefined]

登录查看答疑
Art historian: Unlike many artistic traditions that sought to depict plants native to the local area in a seasonally appropriate way (for example, depicting scenes of spring with the plants in the appropriate stages of development for that season), seventeenth-century Dutch artists specializing in flower paintings almost exclusively chose to depict exotic species of flowers from outside the local area. Painting such species was worthwhile primarily because the art-buying public had developed a strong preference for images of the exotic. The great botanical centers of the time gave the artists direct access to such flowers, which the artists would freely combine in a single painting, regardless of whether the combined species occurred together in the wild, and depicted each in full bloom, regardless of whether those species bloomed at the same time in nature.

Statement: The art historian makes the point that the species of flowers these Dutch artists chose to paint were 1 largely because the species were 2 .

Select for 1 and for 2 the options that complete the statement so that it is most strongly supported by the information provided. Make only two selections, one in each column.
我选的CE，和EC有什么区别？怎么选出EC的？
0评分
1333浏览

[Undefined]

登录查看答疑
An unusually severe winter occurred in Europe after the continent was blanketed by a blue haze resulting from the eruption of the Laki Volcano in the European republic of Iceland in the summer of 1984.  Thus, it is evident that major eruptions cause the atmosphere to become cooler than it would be otherwise.
Which of the following statements, if true, most seriously weakens the argument above?
C选项为什么就不会有张冠李戴的问题呢，1984和1982的气候情况能一样吗，C里的火山就可以试用于原文的火山吗
0评分
1511浏览

[Undefined]

登录查看答疑
The rate of a certain chemical reaction is directly proportional to the square of the concentration of chemical A present and inversely proportional to the concentration of chemical B present. If the concentration of chemical B is increased by 100 percent, which of the following is closest to the percent change in the concentration of chemical A required to keep the reaction rate unchanged?
为什么这个题一定是相乘不能是相加呢？y=k1A方-k2B （k1,k2大于0 ），也满足题目说的与A方成正比与B成反比啊？但是这道题只有相乘的情况才能选出正确答案
0评分
584浏览

[Undefined]

登录查看答疑
Tiger beetles are such fast runners that they can capture virtually any nonflying insect.  However, when running toward an insect, the beetles intermittently stop, and then, a moment later, resume their attack.  Perhaps they cannot maintain their pace and must pause for a moment's rest; but an alternative hypothesis is that while running tiger beetles are unable to process the resulting rapidly changing visual information, and so quickly go blind and stop.
 
Which of the following, if discovered in experiments using artificially moved prey insects, would support one of the two hypotheses and undermine the other?
答案C是怎么支持一个猜想又削弱另一个猜想的？
0评分
1351浏览

[GWD]

登录查看答疑
The author of the passage implies that which of the following is a possible partial explanation for acquisition behavior during the 1970's and 1980's?
请解释这道题为什么不选C或E，除了正确选项B，我认为文中也正确地提到了这两个选项可以解释acquisition behavior during 1970s and 80s
0评分
962浏览

[OG]

登录查看答疑
The primary purpose of the passage is to
为什么选E不选B
0评分
644浏览

[Undefined]

登录查看答疑
Club X has more than 10 but fewer than 40 members. Sometimes the members sit at tables with 3 members at one table and 4 members at each of the other tables, and sometimes they sit at tables with 3 members at one table and 5 members at each of the other tables. If they sit at tables with 6 members at each table except one and fewer than 6 members at that one table, how many members will be at the table that has fewer than 6 members?
提问小梅老师 这道题求讲一下 我没什么思路 带入数字得的是3
0评分
654浏览

[Undefined]

登录查看答疑
A photography dealer ordered 60 Model X cameras to be sold for $250 each, which represents a 20 percent markup over the dealer's initial cost for each camera. Of the cameras ordered, 6 were never sold and were returned to the manufacturer for a refund of 50 percent of the dealer's initial cost. What was the dealer's approximate profit or loss as a percent of the dealer's initial cost for the 60 cameras?
请问小梅老师 这道题讲讲一下 我算的是19% 原来成本是200每个 亏了6个 每个亏100. 最后得不出答案
0评分
154113浏览

[Undefined]

登录查看答疑
Analytical!
请问may老师，这题该用什么思路来做？
0评分
161222浏览

[Undefined]

登录查看答疑
Analytical!
请问张老师，这道题为什么D不对？我有我觉得second paragraph最后一句话特别指向D
点我领取
免费专项课程
 在线咨询