问题 读图填空题

根能吸收水是因为土壤溶液的浓度          根细胞溶液的浓度。

答案

小于

题目分析:植物吸水还是失水主要取决于细胞内外浓度的大小,当细胞液的浓度大于周围水溶液的浓度时,细胞就吸水,当细胞液的浓度小于周围水溶液的浓度时,细胞就失水,题中植物的根从土壤中吸收水分,说明根毛细胞液的浓度大于土壤溶液的浓度。

点评:此题为基础题,解答此题的关键是理解植物吸水和失水的原理。

阅读理解

阅读理解。

Dear Weiner,

      I think the government should pass a 1aw to stop people from letting their cats run free. There are three

important reasons why you should do it:

     When cats run free, they hide themselves under bird feeders (喂食器) and kill defenseless (毫无防备的)

songbirds. Every time I put up a bird feeder, I find at least one dead bird in my yard. I'm sure all those birds

were killed by cats. And cats don't even eat the birds they kill. Songbirds belong in our parks and gardens, but

cats don't. Dogs never kill poor little birds. I don't know why people don't want a dog in the first place.

     Cats are always using my garden as a litter-box. This is very dirty and makes me feel sick. Children can't

play in the garden when cats have been there. Dogs are usually tied to trees, so they don't cause such trouble.

Cats spread diseases when they use a garden as a litter-box, so I think this should be stopped.

      Finally, letting cats run free is not even good for the cats. Sure, most cats want to go outside. Their

owners like to give them everything they want, just like spoiled children. But cats that stay indoors live much

longer than cats that run free. Cats are always getting hit by cars when they're allowed to run free.

     I'm sure that if you think about all the things I've said, you will work to pass a law stopping cats from

running free. This will improve our environment, make our parks and gardens cleaner, and even help the cats

themselves by making them live. 

     Thank you for your attention to my suggestion.

                                                                                                                                                  Sincerely,

                                                                                                                                         Eve Harringford

1. According to the author, a law should be passed _______.

A. to make people keep their cats indoors

B. to encourage people to keep dogs

C. to prevent people from keeping cats

D. to protect defenseless songbirds

2. Of the following statements, which does NOT support the author's opinions?

A. Cats kill defenseless songbirds.

B. Cats usually hide themselves in litter-boxes.

C. Cats spoil the environment.

D. Cats face more dangers when they run free.

3. From the passage, we can learn that _______.

A. cats should never be allowed to run outside

B. it is against the law to let cats run free

C. the author has a good opinion of dogs

D. Weiner is all for stopping cats running free

4. The author's purpose in writing this letter is to _______.

A. give advice

B. offer information

C. entertain readers

D. tell a story

多项选择题