Every day we spend half an hourmorning exercise。A. doBto doCfor doingDdoing

问题补充：

Every day we spend half an hourmorning exercise。

A. do

Bto do

Cfor doing

Ddoing

答案：

A. do

B. to do

C. for doing

(答案→)D. doing

解析：句意：我们每天花半小时锻炼。Spend time doing sth.花时间做某事，后接动词的ing形式，故选D。