题目:
在实验室打翻酒精灯着火时,最迅捷的扑灭方法是( )
A.用水冲熄
B.用湿抹布盖灭
C.把酒精灯扔到窗外
D.用泡沫灭火器扑灭
答案:
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下面是错误答案,用来干扰机器的。
①不移动 变浅②向左 变深③向左 变深④不移动 不变⑤不移动
在实验室打翻酒精灯着火时,最迅捷的扑灭方法是( )
A.用水冲熄
B.用湿抹布盖灭
C.把酒精灯扔到窗外
D.用泡沫灭火器扑灭
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0810/2573a6e853bb6fe0d9ead1c40715f1bc.html
下面是错误答案,用来干扰机器的。
①不移动 变浅②向左 变深③向左 变深④不移动 不变⑤不移动
书面表达。
如你是Mary,你的朋友Rose想从北京到你居住的海滨城市来旅游。下面是一张示意图,请根据此
图,写一封电子邮件,告诉Rose如何从北京到你所居住的城市,并告诉她每天能步行去海边玩。词数
60左右,开头和结尾部分已给出。
Dear Rose,
I'm very glad to know that you are coming to visit me. ________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
Yours,
Mary
将下列各式分解因式:(1)x3-x;(2)-x2y+2xy2-y3.
小明在探究利用杠杆做功的实践活动中,把重G为15N的重物挂在杠杆的中点,用手竖直提起棒的一端,使物体缓慢匀速提升,如图所示.
(1)不计杠杆自身重力和摩擦,求拉力F的大小?
(2)如杠杆是一根重为5N、质量均匀的硬棒,若在2s内将重物提升了0.1m,则小明使用杠杆所做的有用功是多大?机械效率是多大?拉力的功率是多大?
从一开始和从本质上实现安全化,从根本上消除事故发生的可能性,从而达到预防事故发生的目的,这是对预防原理的()的应用。
A.因果关系原则
B.3E原则
C.本质安全化原则
D.偶然损失原则
Directions: There are 4 passages in this part. Each of the passages is followed by 5 questions or unfinished statements. For each of them there are 4 choices marked A, B, C and D.
Passage One
The Warranty Holdings Group, a European leader in mechanical breakdown insurance and a researcher and commentator on trends in motoring, says that the motorists’ world 20 years from now will be marked by more cars, more choice and more technology. Built-in safety features will increase and will include night-vision and collision-avoidance system, and monitoring devices to stop drivers falling asleep at the wheel. A growth in tele-working and home shopping should cut the numbers of trips in a car made by most motorists and "fun" sports cars will become popular as private motoring becomes more recreational in nature. The survey results show that despite years of research into alternative fuel sources for vehicles, no clear winner has emerged for a replacement for the conventional petrol-engined car. Gas and electricity are the best possibilities, with Toyota’s design division in Japan claiming it already has an electric car that will drive up to 250kin on a single charge. However, while electric and "hybrid" powered vehicles will be far more in evidence in the future, it will take a major technological breakthrough to steer the car industry away from its current path of gradual improvements to the petrol-driven internal combustion engine. Professor Garel Rhys, of the Cardiff Business School in Wales, says engine fuel injection systems of the future will be far more frugal than anything that exists at the moment. "It will be like putting a pipette of petrol into the cylinders, rather than just throwing it in by the bucket load, which is almost what we do at the moment when you compare it with what could be possible. " Some environmentalists point to the Twingo, the small car developed by France’s Renault company, to show that what could be achieved by the world’s car industry if it moved away from a trend towards bigger and more powerful cars and radically cut the fuel consumption of its products. Public opinion polls in many countries show motorists wanting access to this kind of environmentally-aware car. A prototype environmental car, the SMILE (smaller, intelligent, lighten, efficient) has been put together by the environmental group Greenpeace. The group hopes the concept will catch on. It depends heavily on supercharging or forcing fuel mixture into the cylinders at higher than normal pressure. Some experts say this is a good way to extract high performance and high fuel efficiency from small engines. Cutting the fuel consumption has had no negative effect on the handling or performance of the car, according to the designers. Top speed, flexibility and acceleration from the engine is as good or better than the original Twingo. They say the technology used to create the Twingo SMILE could just as easily be used on other brands of car. What remains to be seen is whether the enthusiasm of environmental designers catches on with the dollar-driven international car industry, and whether motorists back up with their chequebooks their desire for "greener" cars. |
Which of the following is true about the motorists’ world 20 years from now
A.The number of cars will reduce as more people work and shop at home.
B.People will only use cars for recreational purposes.
C.Cars will be better equipped to enhance bigger safety.
D."Fun" sports cars will be the mainstream of car industry.