电动势是衡量电源将（）本领的物理量。
A.非电能转换成电能
B.电能转换成非电能
C.热能转换成电能
D.电能转换成热能
参考答案：C
选用 am, is, are, was或 were填空。
1. I five then. Now I _ eleven.
2. Her hair short then. But now her hair long.
3. —You so cute then.
—Yes, but I very naughty, too.
4. They ______ young then. They _ very old now.
5. We _ in Grade Two then. Now we in Grade Four.
6. The dog _ small two years ago. It big now.
正常成人从上切牙到气管隆嵴的距离为（）。
A.17～19cm
B.20～22cm
C.23～25cm
D.26～28cm
E.29～31cm
