管道的支、吊架安装应平整牢固，塑料管的固定支架与滑动支架的配置与（）密切相关
A.固定支架
B.滑动支架
C.伸缩节
D.固定吊架
参考答案：C
Don't be angry with us. We ________ with you together, but we were busy with our final reports when you called in.
A．would eat out
B．must have eaten out
C．should eat out
D．could have eaten out
多巴酚丁胺（）
A.血管扩张剂
B.血管紧张素转换酶抑制剂
C.β受体激动剂
D.醛固酮拮抗剂
E.β受体阻滞剂
