除去二氧化碳中少量氯化氢气体的方法是使此气体通过( ) A．_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题选择题

除去二氧化碳中少量氯化氢气体的方法是使此气体通过( )

A．锌粒

B．石灰水

C．灼热的氧化铜

D．碳酸氢钠的饱和溶液

答案

答案：D

碳酸氢钠能和盐酸反应产生CO₂，所以选项D是最好的方案，A中锌和不氯化氢，同样氧化铜和氯化氢气体不反应，所以答案选D。

完形填空

完形填空。
Long long ago,there was a swan(天鹅)with golden feathers(金羽毛). She lived in a lake. A woman lived in a small house 1 the lake with her two daughters. They were very poor. They worked hard all yearround, 2 still, they lived a hard life and sometimes they even didn't have enough _3 to buy food. The swan was 4 to see that. She said to herself, "I'11 give one of my 5 to them each day , then they can live a happy life with the money selling my feathers. "That evening , she 6 to the poor woman's house and left a golden feather on the table without saying 7 . From then on,the swan came every day and gave them a feather. The woman was very happy because their life was much 8 than before.But day after day, the woman became greedy(贪婪的). She said to her 9 ,"The swan may fly away one day. If so , we will be poor again. We should take all 10 feathers when she comes next time. " "Oh no,Mom!"cried the daughters,"This will 11 the swan. She helps us a lot ! "But the mother wouldn't listen. When the 12 came as usual, the mother caught her and took all her feathers. But suddenly, the golden feathers 13 chicken feathers. Then , the golden swan said , "Poor mother , I came to 14 you, but you wanted to kill me.Now, I am leaving and will 15 come back. Never be greedy! " With these words , the swan flew away.
( )1. A. above ( )2. A. and ( )3. A. money ( )4. A. happy ( )5. A. presents ( )6. A. flew ( )7. A something ( )8. A. duller ( )9. A. brothers ( )10. A. his ( )11. A. hurt ( )12. A. woman ( )13. A. heard of ( )14. A. trouble ( )15. A. sometirries	B. over B. but B. time B. surprised B. golden coins B. ran B. everything B. better B. sisters B. her B. save B. daughter B. changed into B. help B. always	C. near C. so C. room C. sad C. feathers C. climbed C. nothing C busier C. sons C. their C. protect C. chicken C. looked for C. teach C. usually	D. under D. or D. energy D. scared D. collections D. walked D. anything D. harder D. daughters D. our D. refuse D. swan D. came from D. invite D. never

单项选择题

租用的机械设备应选择（）、维修方便和环境影响达标的设备。

A.整机性能差

B.操作方便

C.效率高

D.故障率低