给下列地形区选择与其相对应的自然景观．

（1）黄土高原 ____ ；（2）内蒙古高原____ ；（3）青藏高原____； （4）东北平原____ ；

A 地势平坦，一望无际;     B    雪山连绵，冰川广布     C   黑土广布，沃野千里     D  土质疏松，沟壑纵横

在哈佛大学图书馆的墙上有一条格言：“此刻打盹，你将做梦；而此刻学习，你将圆梦。”这句话启迪我们（  ）

①要根据自身的独特性，找到适合自己的独特方法            ②学习是一个苦乐交织的过程，是一个实现梦想的过程 

③我们要珍惜受教育的权利，自觉履行受教育的义务       ④社会越发展，选择的机会就越多，选择的难度就越大

Decision-making under Stress

    A new review based on a research shows that acute stress affects the way the brain considers the advantages and disadvantages, causing it to focus on pleasure and ignore the possible negative (负面的) consequences of a decision.

     The research suggests that stress may change the way people make choices in predictable ways.

    “Stress affects how people learn,” says Professor Mara Mather. “People learn better about positive than negative outcomes under stress.”

    For example, two recent studies looked at how people learned to connect images(影像) with either rewards or punishments. In one experiment, some of the participants were first stressed by having to give a speech and do difficult math problems in front of an audience; in the other, some were stressed by having to keep their hands in ice water. In both cases, the stressed participants remembered the rewarded material more accurately and the punished material less accurately than those who hadn't gone through the stress.

    This phenomenon is likely not surprising to anyone who has tried to resist eating cookies or smoking a cigarette while under stress –at those moments, only the pleasure associated with such activities comes to mind. But the findings further suggest that stress may bring about a double effect. Not only are rewarding experiences remembered better, but negative consequences are also easily recalled.

    The research also found that stress appears to affect decision-making differently in men and women. While both men and women tend to focus on rewards and less on consequences under stress, their responses to risk turn out to be different.

    Men who had been stressed by the cold-water task tended to take more risks in the experiment while women responded in the opposite way. In stressful situations in which risk-taking can pay off big, men may tend to do better, when caution weighs more, however, women will win.

    This tendency to slow down and become more cautious when decisions are risky might also help explain why women are less likely to become addicted than men: they may more often avoid making the risky choices that eventually harden into addiction.

 - What can you hear? - I can hear a ____.