问题 问答题 简答题

马铃薯可以施用含氯化肥吗?

答案

参考答案:

以前,人们一直认为氯元素影响马铃薯块茎品质,把马铃薯列入“忌氯作物”,在生产上从不使用含氯化肥,这种看法是不科学的。事实上,只要施用的含氯化肥中的氯元素,浓度在633ppm(633/1,000,000)以下,就对马铃薯没有任何坏影响。还有利于植株生长,产量还有不同程度的增加,块茎淀粉含量与不施氯的基本一样,块茎品质不受影响。因此,在给马铃薯施用全钾化肥时,可以大胆应用氯化钾,这样,既保证了马铃薯对钾肥的需求,也控制了生产成本的上升。

阅读理解

Geena David knew she wanted to be a movie star when she was very young.She was not sure what gave her the idea, but she wanted to look like a movie star.“I have a lot of pictures from my childhood of me wearing sunglasses,”she says.“I used to wear them to watch TV.”

Early movie actors started wearing sunglasses not because they looked good, but because their eyes hurt.The lights used on movie sets were extremely bright and could cause a painful problem known as “Klieg eyes”.It was named after the Klieg brothers who invented the lights.Actors wore sunglasses to give their eyes a rest.But when movie stars began wearing their sunglasses in public, they quickly became a must.

Eventually actors started wearing sunglasses in their movies as well as on the street.Audrey Hephburn wore ultra-cool Ray-Ban sunglasses in the 1961 movie, Breakfast at Tiffany’s.As a result, Ray-Ban sunglasses started to appear more and more in the movies.In 1979, Ray-Ban “Wayfarers” were worn by Jake and Elwoo d in The Blue Brothers.Tom Cruise wore Ray-Ban “Aviator” sunglasses in the 1986 hit, Top Gun.Then in 1997, Will Smith and Tommy Lee Jones made Ray-Ban “Predator” sunglasses famous in Men in Black.

Of course sunglasses aren’t just a fashion statement.The main reason to wear sunglasses is to protect our eyes against UV radiation.UV radiation can damage our eyes, so people now choose their sunglasses carefully.But you don’t have to give up style for safety.The choice of frames and lenses available these days is huge.So you can protect your eyes and still be the coolest person on the beach.

小题1:What is mainly discussed in this passage?

A.The use of sunglasses.

B.The history of sunglasses.

C.The sunglasses wearing.

D.Why movie stars like to wear sunglasses.小题2:Why did Geena David like to wear sunglasses?

A.She was a movie star.

B.She wanted to follow a movie star.

C.Wearing sunglasses was good for her eyes.

D.It was good to wear sunglasses when watching TV.小题3:Early actors’ eyes hurt because ______.

A.they wore sunglasses

B.they went out in the sun too much

C.the lights on movie sets were too bright

D.their scripts were written in very small writing小题4:We may know from this passage that ______.

A.Audrey Hephburn was a famous film star

B.Ray-Ban is the name of sunglasses maker

C.Sunglasses made Top Gun the hit in 1986

D.Men in Black must be an advertisement of sunglasses小题5:Now people wear sunglasses ______.

A.just to protect their eyes

B.for fashion and to protect their eyes

C.because of bright lights

D.because movie stars wear them

单项选择题