题目内容
The experiment needs fifty people divided into two groups of the same size． Group A is to take part in a 7-week exercise, while Group B is not allowed to do any exercise during those seven weeks． On the day before the experiment began, all fifty men took part in a step-test． They were told to step up and down on a 16-inch-long bench at 30 steps a minute for five minutes． After the test each man’s heart-beating was taken and recorded． Then during the seven weeks men in Group A rode a sort of bike-like exercise machine for 15 minutes a day． During the first day ride they were asked to ride very slowly． For the next three days, they were permitted to ride a bit more quickly． And the speed of riding was increased every few days until the end of the experiment, when both Group A and Group B were given the step-test again and the heart-beating was taken again, too． Heart-beating of Group A members was to have dropped to an average of 30 heart beats per minute while that of Group B members remained the same or almost unchanged．
1． How many people were in each group?
A． 100 B． 50 C．25 D． 15
2． The step-test was given ______．
A． after each exercise period
B． only once, at the beginning of the seven-week period
C． at the beginning and at the end of the seven-week period
D． twice to the men in Group A and once to the men in Group B
3． The exercise was planned so that the amount of quick riding _________．
A． increased every few days B． changed every other day
C． increased every other day D． increased every exercise period
4． What did Group A do in their experiment? They ______ ．
A． stepped up and down on a bench each day
B． pushed and pulled the bikes every day
C． were prevented from doing any exercise
D． rode on an exercise machine
5． It seemed that _______ during the whole experiment．
A． Group A did less exercise than Group B
B． Group B did less exercise than Group A
C． Group A did everything
D． Group B did nothing
解析：
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