下列关于物质的分类，合理的是[ ]
A.铅笔芯、橡胶、铁是导体
B.塑料、干木棒、陶瓷是绝缘体
C.铁、冰、玻璃是晶体
D.蜡、食盐、水银是非晶体
答案：B
根据句意及首字母提示完成句子。
1. —Where's your friend?
—She's sitting b______ here deskmate.
2. That musician has w______ many songs.
3. —Has your father been a______?
—Yes. He has been to many countries.
4. Zhang Ziyi is very famous. He Meifeng has always wanted to m______ her!
5. How many tickets can you buy if they are all s______ out?
把℃的冰放入0℃的水中，（周围气温为0℃），过一段时间，则（ ）
A．有些冰会熔化成水
B．有些水会凝固成冰
C．冰和水的多少都没变
D．无法判定
