3、Without a doubt，exercise at any time of the day beats no exercise at all．But which is a better time for exercise，morning or evening?

    In various studies，scientists have found that subjects tend to do slightly better on measures of physical performance—including endurance（耐力），strength output，reaction time and aerobic capacity—between 4 and 7 p．m．There’re quite a few explanations：the body’s temperature and hormone（荷爾蒙）levels peak in late afternoon，making muscles（肌肉）more flexible and producing the best ratio（比率）of testosterone （the muscle-building hormone）to cortisol （the hormone that does the reverse）．

     But these variations have only small effects. And much as one can adjust to waking up at the same time daily, studies have shown that the body can adapt to the time of day that you train. In several long-term studies, for example, scientists randomly split people into groups and instructed them to train only in the morning or only in the early evening. In the end, the morning exercisers generally did better on tests of physical performance early in the day, while the evening exercisers did better when tested later.

     On a practical level, that means that if you plan to run a marathon that starts in the morning, it may be best to schedule your training runs early in the day.

     In general, research suggests that the ideal time to exercise is late afternoon, though the advantages are slight.

1．The scientists have found in their studies that the participants usually ______ between 4 and 7 p.m.

A．score higher in physical tests

B．have highest temperature and hormone levels

C．feel less tired after exercise

D．a(chǎn)re more likely to have exercise

2．At the end of the long-term studies, the morning exercisers must have been tested _______

A．only in the morning

B．only in the evening

C．earlier than the evening exercisers

D．both in the morning and evening

3．Which proverb can be used to explain the idea expressed in the third paragraph?

A．Practice makes perfect.

B．Habit is a second nature.

C．Where there is a will, there is a way.

D．Failure is the mother of success.

4．What was taken into consideration when the scientists tried to find out the best time for exercise?

A．The exercising environment.

B．The kind of sports the exerciser is having.

C．The exerciser's physical condition.

D．The age of the exerciser.

5．Which shows the correct order in which the activities decrease in physiological advantage, generally speaking? （“→” means “better than”）

A．Evening exercise → morning exercise → no exercise at all → midday exercise

B．Evening exercise → morning exercise → midday exercise → no exercise at all

C．Morning exercise → evening exercise → midday exercise → no exercise at all

D．Midday exercise → no exercise at all → morning exercise → evening exercise