单项选择题
How do you treat someone suffering from electrical shock after you secure the source?（）
A.check for respiration B.check for pulse C.treat for shock D.All of the above
单项选择题 Tools with （）handles should be used to check electric circuit.
单项选择题 Before doing maintenance on electrical equipment, you should （）.
单项选择题 While the parallel operation, （） must be used.
