问题 选择题

下列曲线正确的是

A.蒸发KNO3的不饱和溶液

B.向稀盐酸中加足量锌

C.加热KClO3和MnO2混合物制取氧气

D.在稀硝酸中加水

答案

答案:A

题目分析:A蒸发KNO3的不饱和溶液溶质质量分数会增大,饱和后质量分数保持不变;B 开始就会有气体生成,所以曲线从零开始;C 加热KClO3和MnO2混合物反应后有固体生成,所以反应完全后固体质量不可能为零;D 加水稀释硝酸溶液pH值会从小于7开始逐渐无限接近于7.

点评:此题属于数形结合类型的题目,常在选择题比较靠后的位置出现,通常有一定的难度,需要读懂所给的图形才能作对题目,对考生灵活运用知识的能

力要求较高。

单项选择题 B型题
阅读理解

You’re sitting on the train home and the person opposite you yawns(打哈欠). Suddenly, you’re yawning with him, though you’re not tired.

This phenomenon confused scientists for years until a recent study found that people tend to sympathize with fellow humans. Supporting this claim was the discovery that those children who were unable to form normal emotional ties with others did not experience contagious(有感染力的) yawning, which showed that humans communicate regularly with out words.

Hugo Critchley, a neuroscientist, has conducted an experiment recently, which will prove that happiness and sadness can spread like the common cold. According to Critechley, our mind and body are in constant exchange about how we’re feeling. “Emotions are closely linked with states of internal(内部的) responses,” he explained. “ There are also more visible changes in our gestures and facial expression. When we’re in a group, these signals can spread to another person. For example, there’s the obvious tendency to smile when smiled at and there are less obvious changes that reflect emotions of surprise, anger or sadness such as a change in our heart rate and blood pressure.

Hugo Critchley further explained, “Our bodies synchronies and when we like the other person, we ever copy his behavior. Next time you chat with a friend, take note of how you’re sitting— it’s pretty likely that you will be the same. Scientists believe it’s our way of telling each other that we’re partners. Through body language, humans give each other very subtle(微妙的) but clear signals that show emotions.”

So, what lessons can we learn from this? “ Spend time with happy people— otherwise your health could suffer,” said Critchley.” When we’re sad, our body goes into fight or flight mode. But when we’re happy, our body works normally and we feel relaxed and positive. So we look bright, our skin glows, we feel healthy and it affects everyone around us.”

小题1: According to Hugo Critchley, ________.

A.emotions are as visible as facial expressions

B.we yawn more frequently when we have a cold

C.emotions are connected with states of internal responses

D.the change of blood pressure is not linked with the change of emotions.小题2:The underlined word “synchronies” in Paragraph 4 means “_____”.

A.move slowly

B.change rapidly

C.relax temporarily

D.respond accordingly小题3:From the passage we can learn ________.

A.sadness is as contagious as happiness

B.anger is less contagious than friendliness

C.surprise is more contagious than smile

D.surprise is the most contagious among emotions小题4:Which of the following statements is true according to the passage?

A.Emotions have delicate influence on fellow humans.

B.Children like copying the actions of the fellow humans.

C.Scientists are still confused about contagious yawning

D.People tend to communicate more with body language.