What problem does the man have？
A. He found the computer center closed early.
B. He has not finished his paper yet.
C. He had to stay up late typing his paper.
D. His computer is not working.
查看答案
According to the passage, why has migration been called the greatest challenge of the coming century？
A. Because of the change of population.
Because of the coming of the new century.
C. Because of economic and political effects.
D. Because of human beings" conflicts.
The philosophical method mentioned by the author in Paragraph 6 is said to be able to do all of the following EXCEPT______.
A. reducing fanaticism
B. increasing mutual understanding
C. ceasing to suggest the way of life
D. ceasing to inspire a way of life
行为强化的理论与实验研究表明，对于初学某个运动技能或刚刚参加体育活动的参与者，在表现出正确行为后，立即
Why do some people move back to cities？
A. Because they want to be closer to a city life.
Because they can save time driving to work.
C. Because they can save the cost of driving long distances to work.
D. Because they think it"s more convenient to live near the workplace.
微信支付 
支付宝支付