欢迎来到牛牛题库网 牛牛题库官网
logo
搜索

单项选择题

《生活饮用水卫生标准》(GB5749-2006)中锰的含量高限是( )mg/L。

A.0.3
B.0.1
C.1.0
D.0.2
点击查看答案&解析

相关考题

单项选择题
Every human being, no matter what he is doing, gives off body heat. The usual problem is how to dispose of it. But the designers of the Johnstown campus of the University of Pittsburgh set themselves the opposite problem－how to collect body heat. They have designed a collection system which utilizes not only body heat, but the heat given off by such objects as light bulbs and refrigerators as well. The system works so well that no conventional fuel is needed to make the campus's six buildings comfortable.
Some parts of most modern buildings－theaters and offices as well as classrooms are more than amply heated by people and lights and sometimes must be air-conditioned even in winter. The technique of saving heat and redistributing it is called “heat recovery.” A few modern buildings recover heat, but the University's system is the first to recover heat from some buildings and reuse it in others.
Along the way, pit has learned a great deal about some of its heat producers. The harder a student studies, the more heat his body gives off. Male students emit more heat than female students, and the larger a student, the more heat the produces. It is tempting to conclude that the hottest prospect for the Johnstown campus would be a hardworking, overweight male genius.
Which of the following is true of the heating system of the Johnstown campus?（　　）
A.Theheatissuppliedbyhumanbodiesonly
B.Theheatissuppliedbybothhumanbodiesandotherheat-emittingobjects
C.Theheatissuppliedbybothhumanbodiesandconventionalfuel
D.Theheatissuppliedbyhumanbodies,otherheat-emittingobjects,andconventionalfuel
单项选择题
下列( )类型的直管形36W荧光灯管必须采用电子镇流器。
A.T12灯管
B.T10灯管
C.T8灯管
D.T5灯管
单项选择题
哪一个不是HTML5新增的语义化标记元素（    ）。
A．section
B．foot
C．article
D．aside
微信小程序免费搜题

All Rights Reserved 版权所有©牛牛题库网(nntiku.com)

备案号：湘ICP备2022003000号-1

微信扫一扫,加关注免费搜题

微信扫一扫,加关注免费搜题