In the presence of external forces，the center of buoyancy of an inclined vessel is vertically aligned with the（）.
A . center of gravity
B . metacenter
C . center of flotation
D . keel
相似题目
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The lowest temperature at which fuel combustion becomes self-sustaining in the presence of a source of ignition, is defined as the （）
A . auto-ignition point
B . flash point
C . burning temperature
D . fire point
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On a semisubmersible ship，reserve buoyancy is increased by the presence of void spaces above the waterline in the（）.
A . submerged hulls
B . quarters
C . columns and upper structure
D . submerged connecting structure
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The presence of bubbles in a refrigeration system liquid line may （）.
A . promote refrigerant dehydration
B . be absorbed in the receiver
C . cause low condensing pressure
D . carry moisture and lead to corrosio
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The lowest temperature at which a liquid gives off enough vapor to ignite in the presence of an ignition source is called its （）.
A . boiling point
B . flash point
C . viscosity point
D . toxic point
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The lifting pressure of （） is set in the presence of a Surveyor it is locked and cannot be changed.
A . fuel valves of main engine
B . injector pump of main engine
C . safety valves of marine boiler
D . safety valves of a reciprocating pum
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The presence of stratus clouds and a dying wind will usually result in（）.
A . heavy rain
B . heavy snow
C . thick fog
D . clearing skie
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The officer in charge of the engineering watch shall continue to be responsible for machinery operations, （）the presence of the chief engineer in the machinery space.
A . as long as
B . unless
C . despite
D . till
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Combustible gas indicators measure the presence of combustible gas as a percentage of the（）.
A . flash point
B . upper explosive limit
C . lower explosive limit
D . fire point
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The safety valve should be （） in the presence of C/E and Surveyor.
A . tightened up
B . sealed up
C . opened up
D . unscrewed
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The lowest temperature at which the vapor formed from a liquid ignites and continues to burn steadily in the presence of an ignition source is called the（）.
A . flash point
B . fire point
C . upper explosive limit
D . lower explosive limit
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"Cast iron has poor corrosion resistance to sea water, especially in the presence of bronzes" Implies（）.
A . east iron is a cheap material
B . cast iron can pollute sea water
C . cast iron has mere corrosive than bronzes to sea water
D . cast iron is more corrosive to sea water when it meets with bronze
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In restricted visibility, a vessel which detects by radar alone the presence of another vessel shall determine if a close quarters situation is developing or risk of collision exists. If so, she shall（）.
A . sound the danger signal
B . when taking action, make only course changes
C . avoid altering course toward a vessel abaft the beam
D . All of the above
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Books bring us into the presence of the greatest minds that they have ever lived.
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The sentence”involves a perception, not only the pastness of the past,but of its presence” guide us to have a_____sense.
A、onlooker
B、catalysts
C、master
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For the first time when Harry feels the presence of death, () were mentioned to symbolize death.
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Generally speaking, the Chinese cooking，lays emphasis on the complete presence of , aroma and taste.
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In the presence of Tai-me, the Kiowas were revived, healed and energized.
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The ghostly presence was just a (n)_________ sensation of some people.
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The presence of armed guards usfrom doing anything disruptive（).
A.excited
B.irritated
C.prevented
D.encourage
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Why does the professor discuss the presence of zinc in paint pigments？
A．To explain why some paints may deteriorate over the course of time
B．To stress the need for caution when attempting to restore old artworks
C．To show how pigments differ from varnishes and binding agents
D．To show how spectroscopy can help establish the age of a painting
此题为多项选择题。
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听力原文：W: I need your help, John, I feel very nervous whenever speaking in the presence of many strangers. Do you know how to overcome this？
M: Me too. Take it easy. I consider it a natural human response. You just need time and practice. Practice makes perfect.
Q: What does the man mean？
(17)
A．She should follow the human nature.
B．Strangers are nothing to be afraid of.
C．Feeling nervous is nothing improper.
D．She should accept strangers' presents naturally.
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Many researchers believe that the presence of RNA ...
Many researchers believe that the presence of RNA in brain cells is the biochemical basis of memory; that is, the presence of RNA enables us to remember. Because certain chemicals are known to inhibit the synthesis of RNA in the body, we can test this hypothesis. Animals that have learned particular responses can be injected with an RNA inhibitor and then tested for memory of the learned responses. Which of the following test results would most seriously weaken the case for RNA as the basis of memory？
A．After an injection of RNA inhibitor, a wide range of behaviors in addition to the learned responses were affected.
B．After an injection of RNA inhibitor, animals that had not consistently been giving the learned responses were able to give them consistently.
C．After injections of RNA inhibitor, some animals lost memory of the learned responses totally but others lost it only partially.
D．After a small injection of RNA inhibitor, animals responded well, but as the size of the injection increased, they gave fewer of the learned responses.
E．After an injection of RNA inhibitor, animals could not learn a new response.
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In a clinical trial, a chemotherapeutic agent is given to patients with breast cancer metastases. Samples of the cancer cells are obtained and assessed for the presence of death of tumor cells by apop
A．BCL-2
B．p53
C．NF- kappaB
D．Cytochrome P-450
E．Granzyme B
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Travelers,when（)the checks,have to sign the checks in the presence bank or service clerks.
A、buy
B、buying
C、to buy
