在不同的国家，家庭文化往往有很大的差别的原因是 [ ]
A．经济、科技和文化水平的不同
B．地域的差异
C．历史发展的差异
D．人口数量的多少
ABC
用所给单词的适当形式填空。
1. Our English ______ name is Miss Li. (teacher)
2. —Are those your ______?
—No, they aren't. (box)
3. The ______ lesson is very interesting. (three)
4. Is this your bike? No, it's ______. (she)
5. It's a nice book. Please let ______ have a look. (we)
6. I can see three ______ in the room. (people)
磁力驱动离心泵主要有（）组成。
A、泵体
B、叶轮
C、电动机
D、动密封
