单项选择题 自动化仪表管路安装要求中，气源管道采用无缝钢管时，应（）。

单项选择题 下列关于公司合并和分立的表述错误的是（）。

单项选择题 听力原文：M: What kind of food are you fond of?W: I'm fond of sweet things.M- How much do you eat each week?W: I eat a lot of sweet things although I know they are bad for my teeth.What food does the woman, like?A．Food rich in sugar.B．Food low in fat.C．Food high in salt.