下列物质露置于空气中易变质的是
①氯水 ②水玻璃 ③烧碱 ④漂白粉 ⑤绿矾 ⑥亚硫酸钠
A．除⑤外
B．除②③外
C．除②③⑥外
D．全部易变质
D
①氯水中的次氯酸易分解，②Na2SiO3易与空气中的CO2和水反应，③烧碱易与空气中的CO2反应，④漂白粉中的次氯酸钙易与空气中的CO2和水反应生成次氯酸，次氯酸易分解，⑤中的Fe2＋和⑥中SO易被氧气氧化。
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| Nowadays, a hospital always manages to keep its beds full. This is good on the one hand, and it's bad on 1 hand. One day, I went to see a sick friend at the hospital. I first went to the 2 desk, where I could get a permit to visit the patient. 3 I could ask which room my friend was in, the lady set down my name, age, filled out a form and 4 a bell. I was just about to tell her what I was coming for when two men arrived with a wheelchair, 5 me in it and pushed me down the hall. "I'm not 6 ," I shouted. "I'm just looking for a friend." "When he comes," one man said, "we'll 7 him up to your room." In a minute I 8 myself in a small room. In no time they undressed me and covered some other things 9 me. One man said "If you need anything, press the button." "I want to get my 10 back." I begged. "Oh, you can 11 us," a voice said, "Even if the 12 happens, we will see that your wife will get everything." They left and locked the door 13 them. I was trying to think of how to escape by the door when Dr. Ward came in with several of his 14 . "Thank God you finally came," I said. "It hurts that badly?" he asked. "No, on the contrary, I am not ill 15 ." Dr. Ward looked 16 . "If you don't feel any pain, that means it's much more 17 than we expected." Then he turned to his students:"This is the most difficult kind of patient to deal with because he refuses to 18 that he is ill. 19 he won't tell us where it hurts, he will never be well again until we find the hurt out for 20 by doing exploratory surgery (手术探查)." | ||||
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