问题 多选题

中耕松土有助于作物的生长,下列不能成立的理由是(  )

A.促进根细胞对无机盐的吸收

B.增强根细胞的呼吸作用

C.促进无机盐在植物体内运输

D.加速无机盐离子到达根细胞表面

答案

植物的根呼吸的是空气中的氧气.经常松土,可以使土壤疏松,土壤缝隙中的空气增多,有利于根的呼吸,促进根的生长.若土壤板结,土壤缝隙中的空气减少,抑制根的呼吸,也抑制根的生长.

故选:ACD.

单项选择题
单项选择题

The appeal of advertising to buying motives can have both negative and positive effects.

Consumers may be convinced to buy a product of poor quality or high price because of an advertisement. For example, some advertisers have appealed to people’s desire for better fuel economy for their cars by advertising automotive products that improve gasoline mileage. Some of the products work. Others are worthless and a waste of consumers’ money.

Sometimes advertising is intentionally misleading. A few years ago a brand of bread was offered to turned out that the bread was not dietetic (适合节食的), but just regular bread. There were fewer calories because it was sliced very thin, but there were the same number of calories in every loaf.

On the positive side, emotional appeals may respond to a consumer’s real concerns. Consider fire insurance. Fire insurance maybe 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 purchase of fire insurance a worthwhile investment 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 evaluate 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.

The reason why the bread advertisement is misleading is that ().

A. thin slices of bread could contain more calories

B. the loaf was cut into regular slices

C. the bread was not genuine bread

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