( Based on the growth rates of large modern reptiles such as ) the Galapagos tortoise and examination of fossils of juvenile dinosaurs, scientists estimate that the larger dinosaurs probably lived to be between 100 and 200 years old. A. Based on the growth rates of large modern reptiles such as B. On the basis of growth rates of large modern reptiles such as C. Based on the growth rates of large modern reptiles like D. On the basis of growth rates of large modern reptiles, like those of E. Based on the growth rates as those of large modern reptiles like 答案是B，错选了A。科学家基于爬行动物的生长率，估计了恐龙的存活时间。科学家做based on的逻辑主语有错吗？麻烦老师讲解。 (Based on account of various ancient writers) , scholars have painted a sketchy picture of the activities of an all-female cult that, perhaps as early as the sixth century B.C, worshipped a godness known in Latin as Bona Dea "the good goddess". A. Based on account of various ancient writers B. Basing it on various ancient writer's accounts C. With accounts of various ancient writers used for a basis D. By the accounts of various ancient writers they used E. Using accounts of various ancient writers 答案是E，还是错选了A。做题时在AE纠结了好久，因为不确定学者作为“基于不同作家的解释”的主语是不是错的，而且感觉基于要比使用的表达更好，尽管可以确定using的主语是学者，但还是把E排除了，麻烦老师讲解。 因为不知道这两道题是犯了什么错误，所以去有道查了based on 的例句，发现人是可以做主语的：Based on the finding, one might predict that the bank should increase its display and budget. 以及 Based on that representation, the district judge denied a motion to dismiss the new comlaint. 麻烦老师讲解这几个题的区别。

这一题，主要区别在于by trying to与in trying to，为何in trying to好与 by呢？ 还有一个区别是划线最后的have had to与have themselves to之间的区别，为何这里不能用have themselves to呢？尤其是在划线前面已经出现了have themselves to的情况下？

没思路，不知道结合条件一及条件二如何得出X1的值...脑子不好使！

只能做到50的阶乘，乘以2的50次方，再加1 的结果 但是后面怎么思考就不清楚了，遇到这种题该如何去做，有什么直接的方法吗？

请May老师帮忙梳理一下这个题怎么用A排列或者C组合的方法算出答案，我每次遇到这种题似乎都有点毛病，不知道应该用A还是C还是结合...

条件一不是已经表明P是C的数量的两倍吗？而原文条件也说明了P或者C其中任意一个都可能为2/3的总量，而条件一表明P=2C 则总份额就是3C。C/（P+C）=1/3，可以得出答案啊，为什么不能选？

这题我认为主要考点在if与when的连用上以及consider后面接to be或者直接接noun。如果在BC选项it无指代可以排除，ADE三个选项中为何E是最优选项呢？这里情形我认为if和when都呢说得通，而且consider后面接noun或者to be在语法上没有问题。

这题正确选项E为什么which后面没有动词而是接的不定式形式，如果这样which后面就不是完整的句子了啊？

How many positive prime numbers are less than integer n? a) 14<n<20。 b) 13<n<17

这一题C，D两个选项中明显有一点不同就是一个用了but many scientist，一个用了and mant scientist. 从句意来看的话，这句话说了A提出了一个观点，但是很多科学家怀疑，然后转折P这个人之后测出来了。虽然D选项中P做的事情用过去时优于C选项中P用完成时，但我认为C选项连词用的比D好，为什么这题D选项优于C选项？