施工现场临时用电系统重复接地装置设置一般不应少于()处。
A、2处;
B、3处;
C、4处;
D、5处
参考答案:B
患者女,6岁。体检时发现胸骨左缘第二肋间3/6级连续机械样杂音,平时一般体力活动无不适。
首选检查是()。
A.X线胸片
B.心电图
C.超声心动图
D.心血流血池显像
E.冠脉CT
Scientists think they have ____ in their attempt to find the causes of some major disease. [ ]
A. broken through
B. worked through
C. got through
D. gone through