题目内容：

    When it comes to making healthy lifestyle changes, which should come first — changing your diet or becoming more physically active?

Previous studies suggested that providing people with too much information about nutrition and physical activity at once tends to be discouraging. That has led to the popularity of advising people to make changes gradually, and set smaller goals.

So the scientists divided 200 inactive participants who were age 45 or older into four groups. One group was instructed about making diet and fitness changes at the same time, the second group was taught about diet changes first, then fitness changes four months later, the third group changed their exercise habits first and made changes in their eating habits four months later, and the final, control group was not instructed about either diet or fitness changes but about how to manage their stress.

The researchers tracked the groups for a full year. Compared to the control group, the three intervention (干预) groups made healthy changes in their diet. Those who changed their fitness habits first significantly increased the amount of exercise they received daily compared to the other groups after four months. However, at the end of the year, the group that changed both diet and exercise at the same time was the only one that met the nationally recommended targets for both exercise and nutrition levels, while those who worked on improving their nutrition first were unable to meet the recommended levels of fitness after a year. The researchers suspect that changes to diet are easier to make than changes to physical activity.

The findings show, however, that pairing diet and exercise changes may help to overcome some of the barriers people face in adding more physical activity into their lives. If folks change diet and exercise orderly, the scientists say, they may end up placing more importance on the first set of behavior changes and feel less pressured to address the second set.

1.The advice mentioned in the second paragraph seemed       .

A.popular B.dangerous C.scientific D.unsatisfactory

2.Which group made progress earlier than other groups in increasing the amount of daily exercise?

A.The first group. B.The second group.

C.The third group. D.The control group.

3.The reason why those improving their nutrition first failed to meet the levels of fitness after a year might be that       .

A.they might be very lazy

B.they wouldn’t like to change their behavior

C.it is much harder to change physical activity

D.they might put on weight before changing their physical activity

4.Which of the following does the author probably approve of?

A.Pairing diet and exercise changes.

B.Becoming more physically active first.

C.Changing diet and exercise following a fixed order.

D.Changing diet first and placing more importance on it.