60质量水平表示质量特性的缺陷率为百万分之（ ）
A．0.27
B．1.7
C．2.7
D．3.4
参考答案：D
使用行灯照明，要有良好的绝缘手柄和金属护罩作保护。
Do you know where _____. Someone is looking for him.[ ]
A. he is
B. he was
C. is he
D. was he
