产生了特征X射线现象的是()
A.光核反应
B.电子对效应
C.光电效应
D.康普顿效应
E.相干散射
参考答案:C
用too, also 或 either 填空。
1. He _____ watches TV in the evening.
2. My mother is a teacher, _____ .
3. He doesn't go to work by bus, _____ .
4. She is _____ a careful girl.
遇有下列哪些恶劣的气候条件影响施工安全时,严禁拆除作业?()
A.大雪
B.大雨
C.浓雾
D.四级(含)以上大风
E.六级(含)以上大风