请教大全608

1.        Researchers have questioned the use of costly and experimental diagnostic tests to identify food allergies, such as milk, that supposedly disrupt normal behavior.

(A) to identify food allergies, such as

(B) to identify food allergies, like

(C) to identify food allergies, such as to

(D) for identifying food allergies, like that of（C）

(E) for identifying food allergies, such as for

为什么答案不是a ? 而是c?

哪位NN来讲一下FOR + DOING表目的的用法。。我很迷惑

表目的

1. for 表sb目的时，后面只能接名词, 不能用v-ing. 如用动词，只能用to do.

例子：I go to restaurant for a dinner. (正确)

  I go to USA for learning English. (错误)

2. for 后接v-ing时，一般是说明sth的用途.

例：It is a knife for slicing bread.