焊工应掌握一般电气知识，应（）灭火技术，触电急救及人工呼吸方法。
A、熟悉掌握
B、学好
C、知道
参考答案：A, B
The boy became fatter and fatter each day and ＿＿＿made his parents sad.
A．which
B．what
C．he
D．it
输尿管结石最多见的停留部位是
A．肾盂输尿管交界处B．输尿管越过髂血管处C．上1/3输尿管D．中1/3输尿管E．下1/3输尿管
