在平台上使用辘轳提钻机时，作业人员必须必须将安全带系在（）。
A.平台上
B.辘轳上
C.巷道内的锚杆上
参考答案：C
根据首字母提示补全单词。
1. Can I b ____ your bike? Mine is broken.
2. I want to i____ you to my birthday party.
3. Could you please f ____ my dog for me when I am away?
4. We need more drinks and s____. Could you buy some?
5. Lily likes traveling by train, but she h____ traveling by ship.
在概率的统计定义中，对事件的概率要满足（）。
A.PA.≥0
B.P（Ω）=1
C.PA.≤0
D.P（φ）=0
