The experiment show that proper amount of exercise if regularly can improve our health.

问题补充：

The experiment show that proper amount of exercise, if regularly, can improve our health.

A. carry out

B. carried out

C. to carry out

D. being carried out

答案：

A. carry out

(答案→)B. carried out

C. to carry out

D. being carried out

解析：考查分词做状语。proper amount of exercise与carry out构成被动关系。Carried out regularly在句中做条件状语。句意：实验显示，如果经常进行，适当数量的锻炼可以改善我们的健康。