单选题Although the national government has introduced some new laws on this subject, it is the state government which is _____ responsible for pollution control.

单选题A valid identification card can be used to ______.

单选题During the 19th century, Jews in most European countries achieved some equality of status with non-Jews. Nonetheless, at times Jews were harassed by anti-Semitic groups. A. opposed B. exploited C. despised D. annoyed

单选题They ______ hold the meeting today.

单选题When he really does something wrong, he is willing to______.

单选题Which of the following statements is TRUE according to the text?

单选题Why are laws formed?

单选题The company is starting a new advertising campaign to______more customers.

单选题If the machine had been cheaper, it might well have ______.

单选题Juliet is not at work. She is taking a ______until the end of this week. A．vocation B．vacation C．vacancy D．volume

单选题Which of the following shows the correct word stress for"encyclopedia”?

单选题He became quite overbearing and domineering once he had become accustomed to the shown to soldiers by the natives. He enjoyed his new sense of power.

单选题__ is known to the world, Mark Twain was a great American writer. 

单选题Oil is an important ______ material which can be processed into many different products, including plastics.

单选题It is not enough to observe behavior and ______ them with physiological events that occur at the same time.

单选题______ of the households in London owned a car in the early 1950s.

单选题Scientists have been struggling to find out the reason behind blushing (脸红). Why would humans evolve(进化) a 21____ that puts us at a social disadvantage by 22____ us to reveal that we have cheated or lied? Charles Darwin pointed out that 23____ all people of all races blush，animals do not. When it came to explaining the reason，he was 24____ a loss. That has not stopped others from trying. One 25____ is that blushing started out as a way to show we obey authoritative members of the group. Later，as our social interactions became 26____ complex，it became involved with higher，self-conscious 27____ such as guilt，shame and embarrassment. This would seem to put individuals at a disadvantage，but blushing might actually make a person more 28____ or socially desirable. 29____ that women blush more than men，one university researcher suggests that blushing might have evolved as a way for women to 30____ their honesty to men so as to win their support in raising children. Some zoologists also think blushing could have emerged as a way to foster trust. " If you were to go hunting 31____ a stone-faced partner，you could never 32____ what he wants. “he says. Once blushing became 33____ with embarrassment，anyone who did not blush might have been at a disadvantage because we are 34____ likely to trust someone who appears never to feel 35____ about anything. Scientists have been struggling to find out the reason behind blushing (脸红). Why would humans evolve(进化) a 21____ that puts us at a social disadvantage by 22____ us to reveal that we have cheated or lied? Charles Darwin pointed out that 23____ all people of all races blush，animals do not. When it came to explaining the reason，he was 24____ a loss. That has not stopped others from trying. One 25____ is that blushing started out as a way to show we obey authoritative members of the group. Later，as our social interactions became 26____ complex，it became involved with higher，self-conscious 27____ such as guilt，shame and embarrassment. This would seem to put individuals at a disadvantage，but blushing might actually make a person more 28____ or socially desirable. 29____ that women blush more than men，one university researcher suggests that blushing might have evolved as a way for women to 30____ their honesty to men so as to win their support in raising children. Some zoologists also think blushing could have emerged as a way to foster trust. " If you were to go hunting 31____ a stone-faced partner，you could never 32____ what he wants. “he says. Once blushing became 33____ with embarrassment，anyone who did not blush might have been at a disadvantage because we are 34____ likely to trust someone who appears never to feel 35____ about anything. （）