Archaeology as a profession faces two major problems. First, it is the poorest of the poor. Only paltry sums are available for excavating and even less is available for publishing the results (5) and preserving the sites once excavated. Yet archaeologists deal with priceless objects every day. Second, there is the problem of illegal excavation, resulting in museum-quality pieces being sold to the highest bidder. (10) Iwould like to make an outrageous suggestion that would at one stroke provide funds for archaeology and reduce the amount of illegal digging. Iwould propose that scientific archaeological expeditions and governmental (15) authorities sell excavated artifacts on the open market. Such sales would provide substantial funds for the excavation and preservation of archaeological sites and the publication of results. At the same time, they would break the illegal (20) excavator's grip on the market, thereby decreasing the inducement to engage in illegal activities. You might object that professionals excavate to acquire knowledge, not money. Moreover, ancient artifacts are part of our global cultural heritage, (25) which should be available for all to appreciate, not sold to the highest bidder. Iagree. Sell nothing that has unique artistic merit or scientific value. But, you might reply, everything that comes out of the ground has scientific value. Here we part company. (30) Theoretically, you may be correct in claiming that every artifact has potential scientific value. Practically, you are wrong. I refer to the thousands of pottery vessels and ancient lamps that are essentially duplicates of (35) one another. In one small excavation in Cyprus, archaeologists recently uncovered 2,000 virtually indistinguishable small jugs in a single courtyard. Even precious royal seal impressions known as I'melekh handles have been found in abundance (40) —more than 4,000 examples so far. The basements of museums are simply not large enough to store the artifacts that are likely to be discovered in the future. There is not enough money even to catalog the finds; as a result, they 368 (45) cannot be found again and become as inaccessible as if they had never been discovered. Indeed, with the help of a computer, sold artifacts could be more accessible than are the pieces stored in bulging museum basements. Prior to sale, each could be (50) photographed and the list of the purchasers could be maintained on the computer. A purchaser could even be required to agree to return the piece if it should become needed for scientific purposes. It would be unrealistic to suggest that illegal (55) digging would stop if artifacts were sold on the open market. But the demand for the clandestine product would be substantially reduced. Who would want an unmarked pot when another was available whose provenance was known, and that was dated (60) stratigraphically by the professional archaeologist who excavated it? The primary purpose of the passage is to propose (A) an alternative to museum display of artifacts (B) a way to curb illegal digging while benefiting the archaeological profession (C) a wayto distinguish artifacts with scientific value from those that have no such value (D) the governmental regulation of archaeological sites (E) a new system for cataloging duplicate artifacts

@Tina老师，老师，这道题帮忙讲一下b和c选项呗。主要区别在谓语单复数和后面的to provide 还是providing。主语是两个不可数名词and并列，谓语要用复数么？

@陆旭老师 我想问一下 这里面的数字7是哪里来的呀？我想了一下排除0和它本身应该还有8个呀，不是很明白。

@陆旭老师 为什么这道题选b呀？我把（1）代进去能求出答案，把（2）代入则x=5与题目要求不符，求讲解。谢谢

@陆旭老师 这道题思路是什么呀？应该怎么做呢？

这道数学题 我想问问数学老师为什么我的两个方法答案都不对 首先 我理解这道题是问事件M或者R只发生一个的概率 我的第一个方法就是用M发生*R不发生+M不发生*R发生 这样哪里出错了 需要怎么改呢？ 我的第二个方法是用总体减去M和R同时发生的概率再减去M和R都不发生的概率，这里哪里出错了 要怎么改呢？ 谢谢老师的回答！

@英吉老师 我想问一下这道题A选项错在了哪里，算是犯了什么错误？

@英吉老师 这一道题里的c选项还是不是很明白哪里错了，请问这句话要是怎么改就算对了呢？

@徐小梅老师，徐老师您好，第4)题，我也看到了“至少2人”这个字眼，也是按照至少2人来算的。但我是这么理解的：原来男女共有12个人，先从5个女生中取2个人，保证了至少有两个女生，所以是C5^2; 接着，再让剩下的3个女生和7个男生合并，共10人，取3个人（此时不论男女都可以），是C10^3。然后合起来就是C5^2*C10^3。

为什么4）不能直接用C5^2 *C10^3?先从5个女生中选2人，再从剩下的10人中选3。这样我算出来的是1200。但是按照图片上老师的方法算的是596。很疑惑，求老师解答一下，谢谢！

为什么分子是5 就一定有一个分母是2的三次方有一个分子是1呢？