一号工程是指把安全工作放到先于一切，高于一切、重于一切的地位。
参考答案：对
It's ten years since the scientist _______on his life's work of discovering the valuable chemical.
A．made for
B．set out
C．took off
D．turned up
剖视图是（）将机件剖切后画出的图形。
