C. mustn’t be D. mustn’t have been 相关知识点: 试题来源: 解析 答案:A核心短语/词汇:in a terrible mess凌乱不堪,乱成一团 lean 打扫 句子译文:这房间凌乱不堪,乱成一团,不可能已经打扫过的。 解析:本题考查的是情态动词的用法。can't 不可能 ,mustn't 禁止——shouldn't 不应当, would...
Life support, during ventures away from earth's atmosphere, requires man-made system capability to provide clean air for breathing and to carry wastes (material and energy) to disposal. In this system, small fires and contaminant emitters must be controlled. Adsorption is essential to this system...
high grade HEPA filter can even be efficient adsorption filtration of particles with a diameter of less than 0.3, to play a role in purifying the air. Many air purifiers HEPA filters are marked with the words "not washable", I believe that ...
科技 科工机械 DUPOONT FILMTEC BW30
Scientific American is part of Springer Nature, which owns or has commercial relations with thousands of scientific publications (many of them can be found at www.springernature.com/us). Scientific American maintains a strict policy of editorial independence in reporting developments in science to our...
The air volume hood can be measured over a long period of time. Some parts can be cleaned periodically, please follow the instructions below to clean the parts. 1. Weave the cover It can be cleaned with soft cleaning agent and cold water. When cleaning, do not let the air flow hood to...
I'd think artists would love a gizmo like this. How cool would it be to paint a flower with a pen that takes the exact colors from nature and puts them down on a piece of paper? For another use, in a press release about the pens, an interior decorator from Boston known mysteriously...
Small fish will dry in about three days if the air is dry. Large fish will take a week or ten days to dry. After the fish have dried place them in a basket. Cover them with clean paper or large leaves. Then put the basket in a cool dry place off the ground. Make sure as ...
It is generally considered ‘best practice’ to alway keep at least 15% to 20% of the Total Drives’ Capacity to be kept as Empty Space, to allow the system to do general housekeeping tasks. Allowing the computer to drop below these levels will eventually cause reduced or poor system perfo...
aAfter emergency shut-down bags must be cleaned (refer to section 5.4) as soon as scavenging air system and powder discharge valve can be operated 在必须清洗事故停机袋子(之后参见第5.4部分),当换气空气系统和粉末排出阀可以被管理 [translate] ...