120.
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
答案是D，因为FUNCTION AS，所以我也选的D。
我的疑问是：语法笔记说A的错误是不一致，Their与未划线部分the turtle has been的数不一致”但我疑惑的是，如果有一个选项是：its horny jaws function as teeth. 那么就对了吗？
有了in some species之后，the horny jaws 到底是谁的？是跟 some species还是the turtle?
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