此题答案有争议，选D还是E。 我倾向于E。

1. 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

allow + that 承认(不加虚拟)

+ to do/for/doing 允许

E.