When a pencil is partly in a glass of water it looks as if it . A. breaksB. has brokenC.

问题补充：

When a pencil is partly in a glass of water, it looks as if it .

A. breaks

B. has broken

C. were broken

D. had been broken

答案：

A. breaks

B. has broken

(答案→)C. were broken

D. had been broken

解析：本题考查的是as if 引导的让步状语从句中的语气问题，as if引导的状语从句如果与事实一致，不用虚拟语气，如果与事实相反，应用虚拟语气。题中“当铅笔的一部分浸在水中，铅笔看上去好像断了”。而实际上铅笔并未断，与事实相反，前半部分陈述是一般现在时，因而本句是对一般现在时的虚拟，用were broken。