Prep sc by findjuh1

kun861010

4. Although the turtle has been toothless for more than 150 million years, in some contemporary turtle species the moderately sharp and jagged edges of their horny jaws function for teeth.

A. their horny jaws function for teeth

B. its horny jaws function for teeth

C. its horny jaws function as do teeth

D the horny jaws function as teeth do

E the horny jaws function as teeth

这题没答案的，但是我想选e。我觉得这里放its和their指代都不清楚。请高手给个答案。

sayysong

IMO E
A -- for 错
B -- its 错
C -- its 错
D -- as teeth do 完全一致，而题目是说“类似”，所以不能加do

果汁软糖

主句里面有 in some contemporary turtle species ，所以应该用their指代species