蜜丸储存一定时间后，有糖等结晶析出，称为（）
A.返砂
B.风选
C.毛笔头
D.五花层
E.毛茸
参考答案：A
用所给词的适当形式填空。
1. The polar bear ______ (live) in the Arctic.
2. Let's ______ (go) to the zoo and see animals.
3. —Would you like ______ (come) to my home for dinner?
—Yes, I'd love to.
4. The zoo has many ______ (wolf), polar bears and zebras.
5. Here ______ (be) some books.
磁体的磁性起源：电子绕原子核旋转就形成了______，每个原子看做是一个微型小磁针，当这些微型小磁针指向较为一致，物体就具有了磁性．
