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问题 填空题

长期暴露在空气中的浓硫酸、浓盐酸、石灰石、火碱，其中质量会增加的是______（写化学式，下同），质量会减少的是______，质量不变的是______．

答案

浓硫酸暴露在空气中会因吸水导致溶质的质量分数变小；浓盐酸暴露在空气中会因挥发使溶质的质量分数减小；火碱暴露在空气中会因潮解并与二氧化碳反应质量会增加；石灰石在空气中质量基本不变．

故填：H2SO4、NaOH；HCl；CaCO3．

选择题

呼吸的意义是（    ）。

A．完成组织里的气体交换

B．吸入氧，呼出二氧化碳

C．氧化有机物，释放能量

D．合成有机物，净化血液
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单项选择题

D


An Englishman named Phil Shaw invented extreme ironing in 1997 because he was bored doing ironing at home.
Extreme ironing is a special kind of outdoor sport. It combines (使结合)danger and excitement with practical ironing.
Who does extreme ironing People all over the world who like danger do it. There are about 1000 people around the world who do extreme ironing. There are extreme ironing clubs and groups in Britain, Germany, South Africa, New Zealand and the United States. You don’t have to have any special qualifications(资格证明)to do it. In fact, anyone can do it. However, it is better to start ironing in your back yard(院子) before you start to iron on top of a mountain.
There are, of course, some rules in extreme ironing. The ironing must be outdoors. You must take an iron, an ironing board, and something that you actually iron to get the wrinkles out. Outdoors includes faraway and unusual places, such as on top of a mountain, while skiing, snowboarding, skydiving, or under water. There are no limits. The more unusual the better. However, you should plan carefully because weather conditions can suddenly change on mountains, for example. You should not do extreme ironing on your own.
What kind of things should you have Your must have a real iron. Travel irons are acceptable. You must not use plastic or toy irons. The clothes you iron must he at least the size of a hand towel. It shouldn’t be just a handkerchief. The board doesn’t have to be a full-size board, but that is preferred. It must be one meter long and thirty centimeters wide and have legs. You must also have proof (证据) of ironing that is either a photo or a video, and it should show a recognizable landmark. Be aware (意识) that people have already ironed near the top of Everest, the highest mountain in the world, and in the Blue Hole in Egypt, one of the most dangerous places to dive. However, there are still many records to break. Iron on!

Which is the best advice for beginners to do extreme ironing ( )

A．Doing extreme ironing alone.

B．Beginning ironing in their back yards.

C．Starting ironing on top of a mountain.

D．Joining extreme ironing clubs or groups first.
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