The experiment shows that proper amounts
题型：选择题
问题：
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
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