由于构造上的原因()只允许安装在水平管段上。
A、旋塞阀
B、止回阀
C、蝶阀
D、闸阀
参考答案:D
“分配时民生之源”,我国的分配制度是[ ]
A.按劳分配为主体,多种分配方式并存
B.先富带后富,共奔富裕路
C.各尽所能,按需分配
D.既要提倡奉献,又要维护公平
I see four kinds of pressure working on college students today: economic pressure, parental pressure, peer pressure, but self-induced pressure.
A.and
B.or
C.nil
D.with