单选题
Fifty volunteers were alphabetically divided into
two equal groups. Group A to participate in a 7-week exercise program, and Group
B to avoid deliberate exercise of any sort during those 7 weeks. On the day
before the exercise program began, all 50 men participated in a step-test. This
consisted of stepping up and down on a 16-inch bench at 30 steps a minute for 5
minutes. One minute after completion of the step-test, a pulse rate of each
subject was taken and recorded. This served as the pretest for the experiment.
For the next 7 weeks, subjects in the experimental group (Group A) rode an
exercycle for 15 minutes each day. The exercise schedule called for riders to
ride relaxed during the first day's ride, merely holding on to the handle bars
and foot pedals as the machine moved. Then, for the next 3 days, they rode
relaxed for 50 seconds of each minute, and pushed, pulled, and pedaled actively
for 10 seconds of each minute. The ration of active riding was increased every
few days, so that by the third week it was haft of each minute, and by the
seventh week the riders were performing 15 solid minutes of active
riding. At the end of the 7 weeks, the step-test was again
given to both groups of subjects, and their pulses taken. The post exercise
pulse rates of subjects in the experimental group were found to have decreased
an average of 30 heart beats per minute, with the lowest decrease of 28 and the
highest decrease of 46. The pulse rates of subjects in the control group (Group
B) remained the same or changed no more than 4 beats, with an average difference
between the initial and final tests of zero.
单选题
How many people were in each group?
A. 100.
B. 25.
C. 50.
D. 15.
【正确答案】
B
【答案解析】解析：由文章第一句话可知，50个志愿者被平分到两个组，每组应有25个人。
单选题
The step-test was given ______.
A. at the beginning and at the end of the 7-week period
B. after each exercise period
C. only at the beginning of the 7-week period
D. only at the end of the 7-week period
【正确答案】
A
【答案解析】解析：由文中可知，在为期7周的实验始末分别进行了一次阶梯测试。
单选题
When were pulse rates taken?
A. After every exercise period.
B. Every time the ratio of active riding was increased.
C. Every day.
D. After each step-test.
【正确答案】
D
【答案解析】解析：由文中可知，在每次阶梯测试后都要测量脉搏。
单选题
What did Group A do in their program?
A. They stepped up and down on a bench every day.
B. The didn't do any exercise.
C. They rode on an exercycle every day.
D. They pushed handle bars every day.
【正确答案】
C
【答案解析】解析：由文章第一段第七句For the next 7 weeks, subjects in the experimental group (Group A) rode an exercycle for 15 minutes each day可知。