当m取何值时，函数 $y=\frac{1}{3x^{2m+1}}$ 是反比例函数？

阅读下面语段，按要求答题。

       岁月的山峦积淀着沧桑，生命的泉水涤荡着chéng澈，心灵的花草弥散着芳香。这梦一般的岁月纯净而美好。悠然行走在美丽的世界里，让自己跨越的姿势①（A．粗犷B．优雅）而蹁跹。优雅是生活的姿态。优雅的生活，就是在某个细雨霏霏的春日里，双手托腮，独坐窗边，聆听窗外细雨独奏的美妙乐声；优雅的生活，就是严热的夏季，静坐大树下，感受微风带来的丝丝凉意；优雅的生活就是在②（A．天高气爽B．狂风暴雨）的秋季，慢步原野，与落叶对话，和秋雨相伴；优雅的生活，就是在白雪皑皑的冬季，jū一捧雪花，握一份惬意。

电热器是利用电流的____来工作的．某发热元件的阻值为420Ω，通过的电流为1A，通电10min产生的热量是____J，这些热量能使2kg的冷水温度升高____℃．水的比热容为4.2×10³J/（kg•℃）．

阅读下面短文，从短文后所给的A、B、C、D四个选项中选出能填入相应空白处的最佳选项。

    Hi, everyone. I'm Daming. I come from a family 1 five people. They are my grandparents, my parents and me. We live in a tall building in Shanghai in the 2 of China. Our apartment is big and 3. We're living a happy life. My grandfather doesn't work now. He often tells me something about his 4.

    My grandfather 5 born in 1958in a small village. At that time, there wasn't a 6 in the village. 7. My grandfather couldn't go to school. There was a 8 behind my grandfather's house. The water was clean and there were lots of fish in it. People in the village were friendly and they got on well with each other. People were busy on the farm all day. There were many interesting games for children to play. It was great for my grandfather to 9 other children, so he wasn't 10. My grandfather often says, “the life in the past was hard, but it was happy too.”