The experiment shows that proper amounts of exercise,if ______ regularly,can improve our health
问题描述：
The experiment shows that proper amounts of exercise,if ______ regularly,can improve our health
A.being carried out
B.carrying out
C.carried out
D.to carry out
为啥不是A?
答
这里是省略了相同的主句及be动词,整句完整的话应该是：The experiment shows that proper amounts of exercise,if the proper amouts of exercise is carried out regularly,can improve our health.或者the proper ...