气瓶和化工管道上所涂的红、黄等颜色也是安全色。
参考答案：错
As most of their houses were badly damaged after the earthquake，many people had to be________in
a stadium.[ ]
A．put away
B．put out
C．put up
D．put off
重整催化剂的主要性能指标有（）
A.活性
B.选择性
C.稳定性
D.抗水性
