"One or two free admission days at slow time." "Slow times" here means ______

A．how people can make their life fit their cycle
B．whether everyone has a daily cycle or not
C．why people have their energy cycle of body at different times
D．what will happen in the family if the couple fail to realize which cycle each member has.

A．one should get up earlier if he wants to work better at his low point in the morning
B．one can change his cycle
C．whenever you feel hot, your energy cycle reaches the highest
D．your cycle must be in the morning if you can get up early