小型氟利昂冷藏库用的吊顶冷风机电机烧毁会出现（）。
A、热继电器保护
B、热继电器烧毁
C、接触器触点烧蚀
D、短路保护
参考答案：D
根据句意和首字母提示填写适当的单词。
1. They have sweaters at a very good p _____.
2. —Excuse me. What's her telephone number?
—S _____, I don't know.
3. Look at the map! Can you s _____ China on it?
4. E _____ of the students in our class has an English dictionary.
5. Wang Jing is a good boy. He h _____ his friends a lot.
孕几周时，超声可检测出脐带回声（）。
A.8周
B.12周
C.16周
D.20周
E.24周
