选词填空

从方框中选择正确的单词并用其适当形式完成下面的句子。

小题1:Are there __________ computers in your classroom?

小题2:You can see two _________ in our school.

小题3:Tony is my friend. I often go to school with           .

小题4:Candy, ice cream and cola are ___________ food and drink.

小题5:________ your sister a student?

关于晶体和多晶体，下列说法正确的是[ ]

A．有规则的几何外形的固体一定是晶体

B．晶体在物理性质上一定是各向异性的  

C．晶体熔化时具有一定的熔点    

D．晶体和非晶体在适当的条件下是可能相互转化的