问题
选择题
保持水的化学性质的最小微粒是
A．水分子
B．氢原子
C．氧原子
D．氢原子和氧原子
答案
答案：A
题目分析：分子是保持物质化学性质的最小微粒。水是由水分子构成的，保持水的化学性质的最小微粒是水分子，故选A。
点评：本题难度不大，主要考查分子、原子的基本概念。
搜题请搜索小程序“爱下问搜题”
保持水的化学性质的最小微粒是
A．水分子
B．氢原子
C．氧原子
D．氢原子和氧原子
答案：A
题目分析：分子是保持物质化学性质的最小微粒。水是由水分子构成的，保持水的化学性质的最小微粒是水分子，故选A。
点评：本题难度不大，主要考查分子、原子的基本概念。
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| One Saturday, I got a phone call about electrical problems. Since I am not an electrician, I quickly 1 that the woman on the line had the wrong number. The woman on the phone sounded extremely 2 as her electricity wasn't working. Her 3 tried to replace a wall switch(开关), but now some of their lights wouldn't be on, and the heat had 4 . The woman thought she was 5 an electrician who had done work for her in the past. I had just recently changed my 6 and she got me instead. I'm not an electrician but I do work with 7 . I 8 her that she had the wrong number, and I didn't know what her old electrician changed his number to. She 9 , and we said goodbye. After I hung up the phone I thought 10 I could help her so I dialed back and found out she was just one town over. When I got to her house, I told her I would help her, but I would not 11 any money. This confused (使迷惑)her and she asked 12 I would bother if I wasn't getting paid. I told her it was an act of 13 and to "pay it forward". The couple, who were both retired, seemed 14 and said they had never met anyone like me. Her husband had fixed the 15 switch which was causing a short(短路). After I was done, they thanked me and tried to give me some 16 . I told them I wouldn't accept anything, and that the best 17 would be to find someone else to help out. I 18 said that if they can't find someone else to repay then just be extra nice to each other. They were both unbelievably happy that I 19 to solve their electrical problems quickly, but I think I was even 20 at the opportunity to help them. | ||||
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