4 You will succeed in the end you give up halfway. A. even ifB. as thoughC. as long asD.

问题补充：

4 You will succeed in the end you give up halfway.

A. even if

B. as though

C. as long as

D. unless

答案：

A. even if

B. as though

C. as long as

(答案→)D. unless

解析：选 D。unless 意为“如果不”、“除非”，用以引导一个条件状语从句。