题目内容
（请给出正确答案）
A.pressurize the system to test for leaks
B.bleed off all pressure within the system
C.operate the machine until it reaches normal temperature
D.disconnect the pump pressure control switch
简答题官方参考答案
（由简答题聘请的专业题库老师提供的解答）
更多“Before performing any maintenance on a hydraulic system storing energy in an accumulator,”相关的问题
A．usage
B．ground
C．practice
D．manner
For semi-professional artists, performing before the public is a good chance______.
A．to improve themselves in their career
B．to help train amateur performers
C．to make friends with superstars
D．to get involved in profitable business
A researcher is performing a two-tailed related samples (matched pairs) t-test. A total of 12 people are in the sample, and before and after measures are taken. The observed t-value for this is –1.84. The level of significance is 0.05. The correct decision is to _______.
A、do not reject the null hypothesis
B、reject the null hypothesis
C、take a larger sample
D、use the z-table instead of the t-table
A.Electric power and starting air
B.Lube oil standby pump and control air
C.Hydraulic switch and engage jacking gear
D.Motor drain and pneumatic control system power
To: All employees
From: Jane McKinley
Date: Monday, 29 March 2007
Subject: Computer maintenance
We will be performing routine maintenance on the computer system this Friday, March 2, starting at 6 A.M. We will be restarting the main computer, which will result in a brief loss of services at some points during the one-hour maintenance.
A brief message will appear on screen five minutes before the maintenance occurs. It instructs computer users to save all data and exit all programs. After the maintenance is completed, users may resume working.
What will happen this Friday？
A．Computer services will be interrupted temporarily.
B．New computers will be installed.
C．Maintenance workers will take a break at 6 A.M.
D．There will be a computer competition held this Friday.
According to the speaker, as an investor you should do the following EXCEPT ______.
A．researching financial pages of the Wall Street Journal
B．keeping an eye on the stock market
C．consulting an expert on investment
D．searching for as much information as possible about the listed companies
听力原文：M Is Ronaldo going to visit the Barcelona office while he's in Europe？
W No, it's not on his schedule. He'll be in Rome for 3 days, then in Munich for 2, and then a few days in London before flying back here on the 16th.
M I think he should stop off in Barcelona as well. They're our best performing office in Europe this year.
W That's true, and that's why Ronaldo doesn't think it's necessary to visit there. We think the focus of his trip should be the offices that aren't doing so well.
What does the man want Ronaldo to do？
A．Tour the factory in London
B．Postpone his trip to Europe
C．Give him a copy of his schedule
D．Visit the company's office in Barcelona
Marian Anderson had a brilliant singing career which began a the age of six when she leamed spirituals' at the Union Baptis Church in her hometown of Philadelphia. Her tour of Europe in the 1920s drew vast acclaim; however, when .she returned to the United States she was still barred from performing on the American operatic stage. After she was prevented from singing in Washington's segregated Constitution Hall in 1939 Eleanor Roosevelt intervened and arranged for her to perform at the Lincoln Memorial. A crowd of 75, 000 people came to watch her sing before the Memorial. Her beautiful contralto voice was breaking down racial barriers, showing Americans that black had a profound contribution to make to Americans cultural life. Eventually, she became the first African-American singer to perform at New York's Metropolitan Opera in 1955. In her many years of touring she had to endure a racism that forced her to enter concert halls and hotels through service entrances. Her grace under this stress showed a moral perseverance that paralleled that of the famous Martin Luther King, Junior.
听力原文： (16) Daniel Hale Williams was an example of a brilliant African-American doctor who managed to find success despite the obstacles white Americans placed in front of him. He was born in 1856 in Hollidaysburg, Pennsylvania. Almost immediately after graduating, (17) he needed to open his own office because at that time no Chicago hospitals would allow black doctors to "use modern facilities and equipment to complete their medical training and care for patients". After two years of successfully running his own hospital, Daniel Hale Williams was confronted with an operation that had never been accomplished. While working in the emergency room, a black express man, James Cornish, rushed in with a knife trauma into his chest. (18) None of the other doctors seemed to know what to do since the external bleeding had stopped, plus there was no way for them to see what was happening inside his chest. This was because there were no x-ray machines available to the doctors, because they were not yet discovered. As the night progressed, Cornish's state began to diminish. After careful evaluation and assessment, Daniel decided that performing open heart surgery on Cornish was the most promising procedure for them to take. Daniel took on the challenge of performing an operation without much technology or advancement. While in the operating room, Daniel "decided to operate on the left side of the chest cavity. (19) The surgery was a success and James Cornish lived for twenty years after the operation was completed. With all of this agony and strength, Daniel Hale Williams became the first person to perform. a successful heart surgery."
16. What is the purpose of the passage？
17.Why didn't Williams work at a hospital？
18.Why hadn't open heart surgery been performed before？
19.How do we know the operation was really successful？
(7)
A．To talk about Daniel Hale William's life.
B．To show how racial discrimination was.
C．To show how an African American paid off.
D．To demonstrate the first open heart surgery.
根据下面材料，回答题。
Sleep-Smart
Do you wake up every day feeling too tired, or even upset？ If so, then a new alarm clock could be just for you.
The clock, called Sleep-Smart, measures your sleep cycle, and waits ____51____ you to be in your lightest phase of sleep before arousing you. Its makers say that should ____52 ____you wake up feeling refreshed every morning.
As you sleep you pass through a sequence of sleep states- light sleep, deep sleep and REM (rapid eye movement) sleep--that ____53____ approximately every 90 minutes. The point in that cycle at which you wake can ____54____ how you feel later, and may even have a greater impact than how much or little you have slept. Being aroused during a light phase ____55 ____you are more likely to wake up energetic.
Sleep-Smart ____56____ the distinct pattern of brain waves produced during each phase of sleep,via a headband equipped ____57____ electrodes (电极) and a microprocessor. This measures the electrical activity of the wearer&39;s brain, in much the ____58____ way as some machines used for medical and research ____59____, and communicates wirelessly with a clock unit near the bed. You ____60____ the clock with the latest time at ____61____ you want to be wakened, and it then duly (适时地) wakes you during the sleep phase before that.
The____ 62____ was invented by a group of students at Brown University in Rhode Island ____63____ a friend complained of waking up tired and performing poorly on a test. " ____64____ sleep-deprived (剥夺)people, we started thinking of ____65____ to do about it," says Eric Shashoua, a recent college graduate and now chief executive officer of Axon Sleep Research Laboratories, a company created by the students to develop their idea.
_____________ 查看材料
A.beside
B.near
C.for
D.around
警告：系统检测到您的账号存在安全风险
为了保护您的账号安全，请在“简答题”公众号进行验证，点击“官网服务”-“账号验证”后输入验证码“”完成验证，验证成功后方可继续查看答案！
