设矩阵A=的特征方程有一个二重根，求a的值，并讨论A是否可相似对角化．

属于Ⅰ相反应的代谢反应是（）

A.硫酸结合反应

B.氧化反应

C.谷胱甘肽结合反应

D.甲基化作用

E.乙酰化作用

完全预混燃烧只在工业、少年宫中广泛应用。

阅读理解。

     Advertising can have both negative and positive effects. Consumers may be convinced to buy a product

of poor quality on high price because of an advertisement. For example, some advertisers have appealed to

(迎合) people's desire for better fuel economy for their cars by advertising automotive products that improve

gasoline mileage (英里数). Some of the products work. Others are worthless and a waste of consumers'

money.

     Sometimes advertising is misleading on purpose. A few years ago a brand of bread was offered to dieters

(节食者) with the message that there were fewer calories (热量单位, 大卡) in every slice. It turned out that

the bread was not dietetic (适合于节食的). But there were the same number of calories in every loaf.

     On the positive side, Advertising may sometimes respond to a consumer's real needs. Consider fire

insurance (保险). Fire insurance may be sold by appealing to fear of loss. But fear of loss is the real reason

for fire insurance. The security of knowing that property is protected by insurance makes the buy of fire

insurance a worthwhile investment (投资) for most people. If consumers consider the quality of the insurance

plans as well as the message in the ads, they will benefit from the advertising.

     Each consumer must be clear about her or his own situation. Are the benefits of the product important

enough to justify buying it? Advertising is intended to appeal to consumers, but it does not force them to buy

the product. Consumers still control the final buying decision.

1. The reason why the bread advertisement is misleading is that _____. [ ]

A. the total number of calories in the loaf remained the same

B. thin slices of bread could contain more calories

C. the loaf was cut into regular slices

D. the bread was not real bread

2. The passage tells us that _____. [ ]

A. advertisements often force consumers into buying things they don't need

B. the buying motives of consumers are controlled by advertisements

C. sometimes advertisements really sell what the consumer needs

D. fire insurance is seldom a worthwhile investment

3. It can be inferred from the passage that a smart consumer should _____.[ ]

A. be familiar with various advertising skills

B. think carefully about the benefits described in the advertisements

C. know the nature of advertisements is cheating

D. avoid buying products described in the advertisements

4. The passage is mainly about _____. [ ]

A. ways to protect the interests of the consumer

B. how to make a wise buying decision

C. the function of advertisements in increasing sales

D. the positive and negative aspects of advertising

两目干涩，视物昏花，甚则夜盲，多因

A．肝气上逆
B．肝火上炎
C．肝阳上亢
D．肝风上扰
E．肝血不足

物流的定义是什么？构成要素有哪些？