要证明一氯甲烷中氯元素的存在可以进行如下操作，其中顺序正确的是（） ①加入AgN

下列关于有机物说法正确的是(　　)

①制乙酸乙酯时，把乙醇和乙酸依次加入浓硫酸中

②用灼烧的方法可以区别丝和棉花

③油脂水解可得到氨基酸和甘油

④纤维素和淀粉都是多糖，二者互为同分异构体

⑤溴乙烷、油脂和蛋白质在一定条件都能水解

⑥乙醇中是否含水，可用金属钠来检验

⑦乙烯和乙烷都能发生加聚反应

⑧蛋白质水解的最终产物是多肽

A．①②③⑧　　　　　　

B．②⑤

C．④⑤⑥⑦

D．①⑤

钢结构的连接方法分哪几种？

Would you eat a ready meal from the fridge rather than cook from scratch? Have you been doing internet shopping rather than going to the stores? What can't you be bothered to do?

A study into how lazy British people are has found more than half of adults are so lazy they'd catch the lift rather than climb two flights of stairs.

Just over 2000 people were quizzed by independent researchers at Nuffield Health, Britain's largest health charity. The results were astonishing.

About one in six people surveyed said if their remote control was broken, they would continue watching the same channel rather than get up.

More than one third of those questioned said they would not run to catch a bus. Worryingly, of the 654 respondents with children, 64% said they were often too tired to play with them.

This led the report to conclude that it's no wonder that one in six children in the UK are classified as obese (very fat) before they start school.

Dr Sarah Dauncey, medical director of Nuffield Health, said: "People need to get fitter, not just for their own sake, but for the sake of their families, friends and evidently their pets too.

"If we don't start to take control of this problem, a whole generation will become too unfit to perform even the most rudimentary of tasks."

And Scotland's largest city, Glasgow, was shamed as the most inactive city in the UK, with 75% surveyed admitting they do not get enough exercise, followed closely by Birmingham and Southampton, both with 67%.

The results cause serious challenges for the National Health Service, where obesity-related illnesses such as heart disease and cancer have been on a steady increase for the past 40 years and are costing billions of pounds every year.   

71. What causes children in the UK to be obese?  

A. Eating ready meal            B. Watching TV

C. Doing Internet shopping      D. Being lazy

72. What can be inferred from the passage?  

A. British people are too lazy to do anything.

B. Internet shopping will do harm to your health.

C. Many people would not run to catch a bus in Britain.

D. People should be more active and take regular exercise to keep fit.

73. Which of the following is Not true according to the passage?  

A. One sixth of British people use remote control when watching TV.

B. People will benefit not only themselves but their families by getting fit.

C. Fatness can cause diseases such as heart disease and cancer.

D. More people get obesity-related illnesses now than 40 years ago.

74. What does the underlined word rudimentary most probably mean?

A. basic          B. serious       C. vital       D. hard

75. All the following are among the most lazy cities in the UK except ___________. 

A. Glasgow    B. Birmingham      C. Nuffield     D. Southampton

在实际生产中,一般是孔较难加工,则优先选择基轴制,减少加工难度

情报评估分为（）个等级。

A、5

B、4

C、3

D、2