问题 选择题

主链为5个碳原子的C7H16的同分异构体中,其中一种同分异构体A的核磁共振氢谱有3个峰且面积比为1︰1︰6,则A的一氯代物的同分异构体的数目为

A.2

B.3

C.4

D.5

答案

答案:B

题目分析:该烃结构式中含有3个甲基,则该烷烃只有1个支链,

若支链为-CH3,主链含有6个碳原子,符合条件有:CH3CH(CH3)CH2CH2CH2CH3,CH3CH2CH(CH3)CH2CH2CH3

若支链为-CH2CH3,主链含有5个碳原子,符合条件有:CH3CH2CH(CH2CH3)CH2CH3

支链不可能大于3个碳原子,故符合条件的烷烃有3种。

故选B。

点评:考查烷烃的结构、同分异构体书写,难度中等,掌握烷烃同分异构体的书写方法。

单项选择题
阅读理解

BEIJING--Alarmed by the overreaching ambitions of many Chinese provinces to grow at all costs, China’s top economic chief is calling on officials to calm down and spare a thought for the environment.

Zhang Ping, who heads China’s National Development and Reform Commission, the central economic planning agency, said only five or six of China’s 30 provinces are targeting annual economic growth of 8 percent or 9 percent.

The remaining provinces are aiming for growth rates of more than 10 percent this year, with some wanting to double economic output in the coming five years.

“China has a planned energy supply of about 4 billion cubic tons of coal equivalent(等量的)for the next five years, and this is not enough to meet demands for economic growth to double,” he was quoted as saying on the news portal Sina.Com.

Beijing is increasingly concerned with the ambitions of Chinese provinces across the country to chase high growth despite the central government’s urgent request for a more moderate and sustainable(可持续的)pace of expansion.

Years of rapid economic growth has taken a toll on China’s environment, with Beijing trying to remove some of the damage now.It has an annual growth target of 7 percent for the next five years, well down from last year’s 10 percent.

Zhang said Beijing has asked local governments to take into account the supply of “energy, environment, water and land” to set more reasonable growth targets.

小题1:Which of the following statements is TRUE according to the passage?

A.Many Chinese provinces are alarmed by Beijing.

B.Zhang Ping is an expert and economic chief from www. Sina.Com.

C.The supply of the coal in China is not sufficient(足够的) for the next five years.

D.Few Chinese provinces are aiming for economic growth rates of less than 10%.小题2:The underlined phrase “taken a toll on” in the sixth paragraph means “_________”.

A.looked forward to

B.paid attention to

C.caused damage to

D.attached importance to小题3:The general idea of the whole passage can be that ________.

A.China’s economy is developing

B.China’s top chief places more emphasis on the environment

C.all Chinese provinces should slow down their economic growth rates

D.economic high growth should go hand in hand with environmental protection小题4:What could be the best title for the news?

A.Economic Development

B.Energy Supply

C.Sustainable Development

D.Environment protection