PREP2-13 NN请进

zm_patrickS

One of the earliest known birds with a beak and contour feathers, Confuciusornis sanctus, with large clawlike "thumbs" on its wings, which probably helped them to climb up to a launching position for flight.

(A) with large clawlike "thumbs" on its wings, which probably helped them to

(B) with large clawlike "thumbs" on their wings, which probably helped it to

(C) had large clawlike "thumbs" on its wings, which probably helped them

(D) had large clawlike "thumbs" on its wings, probably to help it

(E) had large clawlike "thumbs" on their wings, probably to help it

答案是D，我记得在哪里看过说，“，to do结尾”的结构一定错误，想请教NN

nymphl

按照错误严重程度来看，C和E选项里it和them是前后不一致的，这一条就足够了，to do还是do并不关键

dakuandakuan

D 至少主谓前后都是一致的，   其他4个选项全部都有主谓不一致的问题， one of the earliest know birds, 谓语应该是 单数， 所以那些 their wings 全部都是错误的， 然后 help them to  也都是错误的 因为只有一种鸟，  虽然我也不明白这个 probably to do  结构， 但是 根据主谓语的判断 只有这个最合适，
我接触了语法大约3个月， 然后在国外呆了3年了，平时主要看看 wallstreet National Geography 我个人感觉，其实美国人的语法 时态是肯定要准确 不能混淆，但是其实很多固定用法 他们自己都很随意的，而且您说的 to do 结尾一定错，  可是这个 probably to do  不在结尾也。