为验证人体呼出的气体中含有较多的二氧化碳的实验装置，瓶内均装入澄清的石灰水。
（1）如果气体的进出均选择弯管，在实验时，应向甲瓶 ，向乙瓶 。
（2）经向两瓶内分别吹气.吸气后，甲乙两瓶的区别是
（3）在本实验中，甲瓶的作用是 乙瓶的作用是说明了
（1）吸气 呼气 （2）乙瓶变浑浊 （3）对照 人呼出较多的二氧化碳
二氧化碳能使澄清的石灰水变浑浊，呼出的气体与吸入的气体相比，二氧化碳的含量增加，对着石灰水吹气，会变浑浊。
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| A king once went to a master (大师)．He wanted to become more powerful than other __1__kings.He sat in front of the master and__2__telling him the purpose of his__3__. The master listened__4__to the king. He then told the king to go to the__5 where a rose plant and a cypress (柏树) plant were growing side by side.He told the king,"They are your__6__.They can teach you what you want to__7__." The king went into the garden,and__8__the two plants but could not__9__what he could learn from them.He went back to the master and asked,"What do you__10__,master? I am not able to understand what and how these plants will teach me." The master took the king to the plants and__11__,"This cypress plant has been next to the rose plant for so many years.Never once has it wanted to become a rose plant.__12__,the rose plant has never wanted to become a cypress plant.If man had been the cypress plant,he would have__13__himself with the rose and felt jealous (忌妒的) at the__14__that the beautiful rose plant was getting from all the people.__15__,if man were the rose plant,he would have__16__ the cypress plant enviously (羡慕地) thinking how__17__ the plant was without the__18__ of being disturbed by people all day!Both of the plants grew very well because they__19__all their energy for their own__20__instead of using it to compete with the other." | |||
| ( )1．A.rich ( )2．A.forgot ( )3．A.transport ( )4．A.patiently ( )5．A.valley ( )6．A.enemies ( )7．A.design ( )8．A.saw ( )9．A.provide ( )10. A.hear ( )11. A.ordered ( )12. A.Similarly ( )13. A.covered ( )14. A.pack ( )15. A.Besides ( )16. A.looked at ( )17. A.heavy ( )18. A.duty ( )19. A.lost ( )20. A.growth | B．handsome B．continued B．visit B．angrily B．bank B．families B．learn B．watched B．show B．find B．explained B．Frequently B．compared B．pay B．However B．waited for B．useful B．mistake B．used B．opinion | C．western | D．neighboring D．suggested D．test D．worriedly D．forest D．teachers D．notice D．heard D．remember D．mean D．requested D．Luckily D．dressed D．message D．Or D．listened to D．poor D．trouble D．received D．victory |