保险公司应当提供每日()小时电话服务，并且工作日的人工接听服务不得少于8小时
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单相半波可控整流电路电阻性负载，控制角α=900时，输出电压Ud是()。
A. 0.45U2
B. 0.225U20.5
C. U2
D. U2
Which of the following is true about the recent annual study ？
A. It is sponsored by 163 countries .
B. It excludes GDP as an indicator.
C. Its criteria are questionable .
D. Its results are enlightening .
A.in the face ofB.in the form ofC.in the way ofD.in the name of
A. in the face of
B. in the form of
C. in the way of
D. in the name of
我国煤矿井下人身安全电流极限值为()
A. 37mA
B. 36mA
C. 35mA
D. 30mA
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