请帮忙看看PP－4题的答案是什么？

请帮忙看看PP－4题的答案是什么？

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

谢谢！

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

---> E is correct

here, "as" is similar to "like"

谢谢mbz, 我原来以为是d 呢，但是通过NN指点，才发觉得是因为此处as 表示作为的意思吧！

记得好像og 里有，sb.acted as ...

Thank you again MBZ,so glad to see you again.