问题 填空题

草履虫的主要食物是______.它在适宜的环境中通过______进行生殖.

答案

草履虫属于动物界中最原始,最低等的原生动物.它喜欢生活在有机物含量较多的稻田、水沟或水不大流动的池塘中,以细菌和单细胞藻类为食,据估计,一只草履虫每小时大约能形成60个食物泡,每个食物泡中大约含有30个细菌,所以,一只草履虫每天大约能吞食43200个细菌,它对污水有一定的净化作用.草履虫属于单细胞动物,主要靠分裂进行繁殖.

故答案为:细菌和单细胞藻类;分裂

阅读理解

阅读理解。

     Tea bag drinking is most Westerns' favorite way of drinking tea. Do you know how it came about?

     The tea bag was invented in 1908 by Thomas Sullivan, an American tea seller. He was sending out free

tea in silk (丝绸) bags for people to try. People put the bags together with the tea leaves into the cup and

added hot water. The tea tasted good, and people thought it was easy to clean the cup. They were not happy

when Sullivan started sending them loose (散的) tea again.

     Sullivan realized that he had a hot new thing in his hands, and he built a machine to pack the bags. As tea

bags became popular, they were changed from silk to gauze (薄纱) and later paper. In 1952, Lipton Tea

made the tea bag even more popular with its invention of the four-sided tea bag. Tea bags were soon a hit

in the UK, and today 85% of the tea in the UK is packed in paper bags.

     However, many people still prefer loose-leaf tea. This is because some tea companies put not very good

tea in their tea bags. But for most drinkers, tea bags are still the easy, tasty way to go.

1. Who invented the tea bag?

A. An English tea seller.

B. Chinese.

C. Lipton.

D. Thomas Sullivan.

2. The tea in silk bags was welcome because ________.

A. the tea in bags was free and very good

B. the tea tasted good and the cup was easy to wash

C. people were happy with the loose tea

D. people didn't know any better way to enjoy the tea

3. The material of the tea bags is usually ________ now.

A. silk

B. gauze

C. paper

D. plastic

4. The underlined sentence "Tea bags were soon a hit in the UK" probably means"________ in the UK".

A. Tea bags soon became popular

B. Tea bags surprised everyone very much

C. Tea bags kicked (踢) the loose-leaf tea out of the market

D. Tea bags weren't allowed to be sold

5. The reading mainly talks about ________.

A. the invention of tea

B. the way of drinking tea

C. the history of tea bags

D. people's favorite tea in the world

单项选择题