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An inert gas system is designed to reduce the possibility of tank explosions by（）.
A . eliminating sparks and fire in the vicinity of cargo tanks
B . removing all hydrocarbon gases from the cargo tanks
C . blanketing cargo tanks with inert foam
D . reducing the oxygen concentration below levels necessary for combustio
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After an explosion，repair of emergency machinery and services should be accomplished（）.
A . after control of fire，flooding，and structural repairs
B . immediately，before the emergency is under control
C . after control of fire，but before control of flooding
D . after stability is restored
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In a diesel engine cooling water system, a pH of 60 indicates a/an （）.
A . slightly acidic condition
B . slightly alkaline condition
C . overtreatment of water
D . neutral condition of water
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Movement of liquid in a tank when a vessel inclines causes an increase in（）.
A . righting arm
B . metacentric height
C . height of the uncorrected KG
D . natural rolling period
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In a few years an intelligent computer will certainly be an____diagnostic.
A . indirect
B . inseparable
C . indisputable
D . indispensable
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The effect of high vapor superheat in a refrigeration system, is a/an （）.
A . increased capacity of the compressor
B . more efficient operation of the thermal expansion valve
C . decreased capacity of the compressor
D . loss of receiver capacity
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An important consideration in selecting a lubricating oil for use in a refrigeration compressor is for the oil to （）
A . have a high viscosity index
B . mix readily with refrigerant
C . have a high freezing point
D . have a low pour point
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If a crankcase explosion occurs in a diesel engine, you should stop the engine and（）
A . immediately open all crankcase relief ports
B . increase crankcase exhauster speed to draw cool air into the engine
C . allow the engine to cool naturally
D . increase crank case scavenge air to remove unburned gase
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A （） boiler is an auxiliary boiler sometimes included in a steamships installation for supplying steam to auxiliaries in port.
A . monkey
B . donkey
C . waste heat
D . mai
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A transformer in an electric circuit serves to （）
A . generate its own electrical power
B . transform electrical energy into mechanical energy
C . increase or decrease circuit voltage as required
D . convert AC current to DC current
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In comparing engines of equal horsepower, higher exhaust gas temperatures occur in a/an（）
A . opposed-piston engine
B . double-acting engine
C . two-stroke/cycle engine
D . four-stroke/cycle engine
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Flame failure in an automatically fired auxiliary boiler can from a/an （）
A . incorrect electrode setting
B . incorrect nozzle position
C . clogged fuel nozzle
D . broken high tension lead
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The minimum concentration of a vapor in air which can form an explosive mixture is called the（）.
A . auto-ignition point
B . flash point
C . lower explosive limit (LEL)
D . threshold limit value (TLV)
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The loss of （） from an air compressor could lead to an overheated air discharge and possibly an explosion in the pipelines leading to the air reservoir.
A、lubricating oil
B、compressed air
C、cooling water
D、sealing ring
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In a virtual environment， what differentiates an x3950 M2？（）
A . Disk space
B . Memory
C . Extra Power supplies
D . CPU speed
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“A souk is an open-air marketplace in an Arab country.” In the sentence, the word “souk” means______.
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In fact, ZYBO is a/an
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根据所听到的内容回答题__________ A. In a post office. B. At an insurance company. C. On an airplane. D. In a movie company.
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With the explosion of digital media in recent year...
With the explosion of digital media in recent years, a growing number of students are spending their time in front of the small screen---whether it’s a Smartphone or tablet. In just two years, the number of US children using digital media has doubled to 72 percent, according to a survey by Common Sense Media.
On average, students spend about two hours a day in front of the screen. Watching TV makes up half of this time. But gradually, the time children spend watching TV is decreasing, with more and more time being given to digital media. Some of the common things kids do with digital media are playing games, watching videos and sending messages to friends.
The digital world can be used very effectively. In the survey, 74 percent of teachers said that digital media would improve students’ learning. As students can quickly get hold of information they need.
However, without guidance from teachers or parents, digital media may have bad influence on students’ attention span and communication skills. So it’s always best to use your smartphone and tablet carefully.
When using digital media, you need to find a balance. Just like study, too much can lead to information overload, and give you a headache. Also, make sure your smartphone or tablet doesn’t take priority over more important tasks. Give your eyes a rest, and remember: offline is just as fun as online.
1. Two years ago, the number of US children who use digital media made up _____.{A; B; C}
A. 72%
B. 36%
C. 74%
2. Which is not TRUE according to the passage？{A; B; C}
A. Using digital media is good for students’ learning.
B. Using digital media can improve students’ communication skills.
C. Students should use their digital media under adults’ guidance.
3. The underlined word “overload” in the last paragraph means _____ in Chinese.{A; B; C}
A. 重叠
B. 夸大
C. 超负荷
4. The article mentions that kids usually use digital media to _____.{A; B; C}
①play games
②send message to friends
③watch videos
④shop online
A. ①②③
B. ①②③④
C. ①③④
5. Why is the time children spend watching TV decreasing？{A; B; C}
A. Because they need a balance of study and entertainment.
B. Because the TV shows aren’t interesting at all.
C. Because they turn to spend more time on digital media.
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What is NOT the cause of the recent explosion in academic movement？
A．Many scholars like to find an isolated place in a remote area so that they can concentrate on their researches.
B．Planes can take scholars here and there.
C．There are more people working in similar fields than before.
D．There are more learning centres than before.
此题为多项选择题。
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听力原文： An explosion in a Pennsylvania coal mine killed one worker Monday, but five other miners escaped. The blast went off 2,300 feet underground at the R&D coal mine in Schuylkill County. Some officials say it appears a blast went off in the anthracite mine when workers detonated the explosives, but that’s still under investigation.
The process right now is to continue the interviews and then get back down underground and complete the inspections and in that way we can complete the investigation as to what happened.
The brother-in-law of the miner killed says 43-year-old Dlae Reightler worked at the mine since he was a teenager and that he dreamed of moving his wife and four children, setting up an auto-repair business.
He did it all his life. He did that and worked on cars in his garage backyard. He enjoyed doing that stuff.
At the mine, the accident knocked out the ventilation system, making it too dangerous for investigators to go down into the mine shaft. Regulators ordered the facility closed until the investigation is complete. The area has the nation’s only deposits of anthracite, a type of hard, clean burning coal. A June inspection of the site turned up no violations and violations detected in August were fixed on site.
The investigation was dangerous because ______.
A．the mine was badly damaged
B．the ventilation system was broken
C．the mine was too deep
D．the safety facility was destroyed
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Staying in a hotel one day costs renting a room in an apartment for a week（）
A．twice many than
B．twice as much as
C．twice the same as
D．twice as many as
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Economists make a distinction between an increase in supply and an increase in quanti
是
否
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Explosive devices are hidden inside ______ in these two packages.
A．portable computers
B．computer printers
C．cell phones
D．digital cameras
