we have planned ahead might change when we put it into practice. A. WhateverB. WheneverC.

问题补充：

we have planned ahead might change when we put it into practice.

A. Whatever

B. Whenever

C. Whoever

D. However

答案：

(答案→)A. Whatever

B. Whenever

C. Whoever

D. However

解析：考查主语从句：根据句意：当我们实施的时候，提前计划的事情可能会改变。用whatever引导主语从句，相当于anything that，B. Whenever无论何时，C. Whoever凡是…人，无论谁，D. However无论怎样，选A。