The new engine must be thoroughly()before being out on the market.
A.tried out
B.tried to
C.tried in
D.tried with
![](https://lstatic.shangxueba.com/sxbcn/h5/images/tips_org.png)
A.tried out
B.tried to
C.tried in
D.tried with
第1题
Impressive and complex【80】it may appear, the rocket, which was【81】in China over 800 years【82】, is a relatively simple device. Fuel that is【83】in the rocket engine changes【84】gas. The hot and rapidly【85】gas must escape, but it can do so only through an opening that faces backward. As the gas is radiated with great force, it pushes the rocket in the opposite direction.
(76)
A.shown
B.been
C.appeared
D.proved
第2题
Usually, there are two reasons to pursue scientific knowledge: for the
sake of the knowledge itself, and for the practical use of that knowledge.
Because this second aspect of science effects the lives of most people, 【M1】______
it is much more familiar than the first. Knowledge must be gained,
however, after it can be applied, and often the most important technological 【M2】______
advances arise from research pursued for its own sake.
Traditionally, new technology has concerned with the construction 【M3】______
of machines, structures, and tools in a relatively large scale. The 【M4】______
development of materials for building bridges, skyscrapers or highways
is an example of this, as it is the development of the internal-combustion 【M5】______
engine and the nuclear reactor. While such activities involve all sections
of the sciences, the overriding goal has been the same, that is, improve 【M6】______
the human condition by finding good ways to deal with the macroscopic 【M7】______
world.
Since World War IL the focus of technological activity underwent
a major change. While the old activities are still pursued, they have been
largely superseded by applications of technology at the microscopic level.
Instead of building large-scale structures and machines, modern-day
technology tends to concentrate on finding improving ways to transfer 【M8】______
information and to develop new materials by studying the way atoms come
together. The silicon chip and microelectronics typify this new technological
tread, as did the blossoming of genetic engineering. The trend can be 【M9】______
expected to continue for the foreseeable decades. 【M10】______
【M1】
第3题
Before using a fixed CO2 system to fight an engine room fire, you must ______.
A.secure the engine room ventilation
B.secure the machinery in the engine room
C.evacuate all engine room personnel
D.All of the above
第5题
A.Slats must be retracted
B.Flaps must be retracted
C.Slats and flaps must be retracted
第7题
A.compression must be low for effective spark ignition
B.compression must be low for required horsepower and torque generation
C.compression must be low to prevent pre-ignition
D.compression must be low to have effective pre-ignition
第8题
A.The engine must be run until it dies from lack of fuel
B.The fuel tank must be inerted with CO2
C.The ignition key may not be in the ignition
D.The vehicle must be inspected for fuel leaks
第9题
Your ship must {speed up}.
A.reduce speed
B.increase speed
C.change speed
D.stop engine
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