问题
选择题
根据下列物质的组成判断，属于氧化物的是（ ）
A．氯化钠
B．红磷
C．铁
D．三氧化二铁
答案
A、氯化钠中不含有氧元素，不属于氧化物．故选项错误；
B、红磷中不含有氧元素，不属于氧化物．故选项错误；
C、铁中不含有氧元素，不属于氧化物．故选项错误；
D、三氧化二铁是由铁元素和氧元素组成的化合物，属于氧化物．故选项正确．
故选D．
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根据下列物质的组成判断，属于氧化物的是（ ）
A．氯化钠
B．红磷
C．铁
D．三氧化二铁
A、氯化钠中不含有氧元素，不属于氧化物．故选项错误；
B、红磷中不含有氧元素，不属于氧化物．故选项错误；
C、铁中不含有氧元素，不属于氧化物．故选项错误；
D、三氧化二铁是由铁元素和氧元素组成的化合物，属于氧化物．故选项正确．
故选D．
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| In a class I teach adults, I recently did something "unpardonable (不可饶恕的)" I gave the class homework! The 1 was to "go to someone you love within the next week and tell them you love them". It has to be someone you have never said those words to before or at least haven't 2 those words with for a long time. Now that doesn't sound like a very 3 assignment until you realize that most of the men were over 35 and were 4 in the generation of men that were taught that 5 emotion is not macho (阳刚的). Showing feelings or crying was just not done. So this was a very 6 assignment for them. At the beginning of our next class, I asked if someone wanted to share 7 happened when they told someone the loved them I 8 expected one of the women to 9 , as was usually the ease, but on this evening one of the men raised his hand first He appeared quite 10 and a bit shaken. As he 11 out of his chair (all 6feet and 2 inches of him), he began by saying, "Dennis, I was quite 12 with you last week when you gave us this assignment. I didn't feel that I had anyone to say those words to and besides who were you to tell me to do something 13 personal?" "But as I began driving home, my 14 started talking to me It was telling me that I knew 15 who I needed to say I love you too." "You see, five years ago, my father and I had a severe 16 and really never solve it since that time. We 17 seeing each other 18 we absolutely had to at Christmas or other family gatherings. 19 even then, we hardly spoke to each other." "So last Tuesday by the time I got home, I had 20 myself was going to tell my father I love him." | ||||
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