Question

_____ these experiments were successfully completed would we think of
going into humans.

A．If only

B．So that

C．Only if

D．Even if

Answer 1

C

试题分析：A.要是…多好 B.如此…以致于 C.只有在…时候 D.即使。句意：只有在这些实验都被成功的完成的时候，我们才会去考虑研究人类。故选C
点评：本题首先同意理解在先，句意理解后，答案就知道了，其次值得注意的是本题中only置于句首时，句子部分倒装。