问题 选择题

物质的熔沸点高低能用键能大小解释的是

A.Na > K

B.O2> N2

C.H2O > H2S

D.SiO2 > CO2

答案

答案:A

题目分析:A.钠的金属键强于钾的金属性,所以熔沸点:Na>K,与键能有关,故A正确;

B.由于氧气的相对分子质量大于氮气,因此范德华力较大,因此熔沸点:O2>N2,与键能无关,故B正确;C.由于水中含有氢键,H2S中没有氢键,使得水的熔沸点变大,氢键不属于化学键,与键能无关,故C错误;D.SiO2是原子晶体,CO2是分子晶体,所以熔沸点:SiO2>CO2,与键能无关,故D错误;故选A。

完形填空

语法填空(共10小题,每小题1.5分,满分15分)

阅读下面短文,按照句子结构的语法性和上下文连贯的要求,在空格处填入一个适当的词或使用括号中词语的正确形式填空,并将答案填写在答题卷标号为31-40的相应位置上。

The year 2009 is the Year of the Ox, which is a representative of the farming culture of China. In the farming economy, oxen are the major animals  31  (pull) plows (犁).

Of course, the good of oxen is not limited to plowing. In fact, they are seen as “boats on land” for their ability to carry loads. Besides, the whole body of an ox is full of treasures, with their meat and milk as food full of nutrition,  32  their skin used to make clothes and shoes.

In the past, oxen played an important role in the  33  (spirit) life of the Chinese. Even today, oxen still play a special part in some folk activities. For example, some people who 1ive in southwest China will cook cattle bone soup and share  34  among family members when holding a ceremony for children  35  reach 13. They believe that the cattle bone soup represents the blood relationship among family members.  36  (express) their love for oxen, people in some  37  areas will run to shake off diseases on the 16th day of the first month by the lunar calendar, and during their run they will take their oxen along, which  38  (indicate) they regard the creature as human.

Because of the contribution of oxen in their lives, the Chinese people are very grateful to  39  animal. In addition, the use of oxen in ceremonies and the thanks people owe  40  oxen help to develop various traditional customs, which becomes an important part of the folk culture of the Chinese nation.

单项选择题