题目

根据句意或提示补全对话。A: Tom, this my brother, Jim.B: old are you, Jim?C: I am seven old. What about you?B: I am (8). Today is my birthday.C: birthday!B: Thank you. 答案：【1】is【2】How【3】years【4】eight【5】Happy下列说法正确的是（　　） A、物质的量就是物质的质量B、摩尔是物质的量的单位C、摩尔质量就是相对分子质量D、阿伏加德罗常数就是6.02×1023