Question

I think you should think twice .Once ______, the decision won’t be easily changed.

1. A.
   making
2. B.
   to be made
3. C.
   being made
4. D.
   made

Answer 1

D
试题分析：句意为：我认为，你应该三思。一旦作出了，决定便不容易改变。once为表条件的用法，引导的部分做状语，其逻辑主语是the decision，与make之间的关系是被动, 故应为done.表被动的含义，所以答案应为D。
考点：考查非谓语动词作状语的用法。