设备故障规律分（）。
A、第一阶段为初期事故期
B、第二阶段为偶发事故期
C、第三阶段为故障多发期
D、第四阶段为故障期
参考答案：A, B, C
根据语意及所给首字母写出句中所缺单词。
l. Peter always talks big. I can't s him.
2. The girl is unfriendly to me, but I don't m that.
3. There is n to eat at home. Let's go to the restaurant.
4. I want to go with you. But my mother doesn't a .
5. The lion is the k of the beasts（野兽）.
TSP和S02的日平均浓度数据统计的有效性是每天至少有( )。
A．16h和18h B．12h和18h C．18h和18h D．12h和18h
