GWD31-26

The particular design of muscles and bones in the neck and limbs of the turtle allow

that it can draw in its exposed parts such that an attacker can find nothing

but hard shell to bite.

A.     allow that it can draw in its exposed parts such that

B.     allow it to draw in its exposed parts, and so

C.     allows for it to draw in its exposed parts and that

D.     allows that it can draw in its exposed parts, and so

E.      allows it to draw in its exposed parts, so that

答案为什么是D呢？

x谢谢！

同问。。。

我选了E，是不是so that前不能有逗号啊？那and so这是什么用法咧？