问题 选择题

欲量取48mL的液体,最好选用的量筒规格为(  )

A.5 mL

B.10 mL

C.50 mL

D.100 mL

答案

A、5mL量筒量取48mL溶液,需10次才能完成,误差太大,故A错;

B、10mL量筒量取48mL溶液,需5次才能完成,误差太大,故B错;

C、50mL量筒量取48mL溶液,能保证测量一次,且量程与液体的取用量最接近,误差最小,故C正确;

D、100mL量筒量精确度差,取48mL溶液,量程与液体的取用量相距甚远,误差太大,故D错.

故选C.

多选题
阅读理解

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

Shopping is not as simple as you may think! There are all sorts of tricks at play each time we reach out for that particular brand of product on the shelf.

小题1:_ Health foods are packaged in greens, yellows or browns because we think of these healthy colors. Ice cream packers are often blue and expensive goods, like chocolates, are gold or silver.

小题2:_ Recently, some kind of pain killer was brought out, but researchers found it didn’t sell well, because the color made the product look weak and ineffective. Eventually, it came on the market in a dark blue and white package—because we think of blue as safe, and white as calm.

_小题3: But quite often a bottle doesn’t contain as much as it appears to.It is believed that the better-known companies spend, on average, 70 percent of the total cost of the product itself on packaging!

The most successful producers know the truth: _小题4: The founder of Pears soup, who for 25 years has used pretty little girls to promote their goods, came to the conclusion: “_小题5:

A.It’s not enough to have a good product.

B.Coloring, for example, varies according to what the producers are trying to sell.

C.Any fool can make soup, but it takes a genius to sell it.

D.The colors tricked the customers into shopping.E. The size of a product can attract a shopper.

F. A good product is an advantage.

G. The colors turned the customers off.