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The discharge flow of a reciprocating pump is （）.
A . steady
B . in pulsation
C . continuous
D . large
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The （） pump discharges a nearly constant amount of liquid regardless of pressure.
A . mixed-flow
B . axial-flow
C . centrifugal
D . displacement
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A safety outlet is provided on the CO2 discharge piping to prevent（）.
A . over pressurization of the space being flooded
B . rupture of cylinder due to temperature increase
C . over pressurization of the CO
discharge piping
D . flooding of a space where personnel are present
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A non-return valve in the air delivery line near to the compressor must be （）type similar to the compressor discharge valve.
A、the low inertia
B、the high inertia
C、the low velocity
D、the high velocity
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The discharge rate or capacity of a centrifugal pump will vary directly as the （）.
A . change in the impeller diameter
B . square of the impeller radius
C . cube of the impeller diameter
D . impeller efficiency for large changes in its size
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When a vessel sees the other ahead or nearly ahead，by night she could see the masthead lights of the other in a line or nearly in a line or both side lights，（）shall be deemed to exist.
A . head-on situation
B . end-situation
C . crossing situation
D . close-quaters situatio
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A seaman lost his continuous discharge book during the voyage. Upon discharge from Articles，he should be issued a（）.
A . letter of service on company letterhead signed and sealed by the master
B . Record of Entry in a Continuous Discharge Book for use in applying for a duplicate book
C . Certificate of Discharge with the white copy forwarded to the Commandant
D . Mutual Release (CG-2119)，and the articles should be annotated as to the lo
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In order to discharge a C02 portable fire extinguisher , the operator must first（）.
A . invert the CO extinguisher
B . squeeze the two trigger handles together
C . remove the locking pin
D . open the discharge valve
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To maintain design discharge pressure from a centrifugal pump, the design clearance must be maintained between the （）.
A . shaft and impeller
B . motor and pump shaft
C . casing and impeller wearing rings
D . lantern ring and impeller
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If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.
A . a low load on the unit
B . a clogged pump suction strainer
C . a blockage in the line between the pump and hydraulic motor
D . the hydraulic motor turning too fast
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Gear pumps are （） type because they discharge a near constant amount of liquid regardless of pressure.
A . positive displacement
B . non-positive displacement
C . mixed-flow
D . axial-flow
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The discharge from a carbon dioxide fire extinguisher should be directed（）.
A . at the base of the flames
B . at the center of the flames
C . to the lee side of the flames
D . over the tops of the flame
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The port clearance for a ship should be granted（）the completion of loading or discharging in the port.
A . before
B . when
C . after
D . during
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When starting a centrifugal pump, the discharge valve should be （）.
A . closed
B . opened fully
C . cracked open
D . partly ope
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Above-normal tides near the center of a hurricane maybe caused by the （）.
A . high barometric pressure
B . jet stream
C . storm surge
D . torrential rai
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A （） in the air delivery line near to each compressor is essential.
A . butterfly valve
B . globe valve
C . gate valve
D . non-return valve
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The terminal indicates to you that they are going to use a booster pump to assist the discharging operation. You start the discharge，and in a few minutes the pressure drops sharply. This could be a result of the（）.
A . booster pump coming on the line and discharging properly
B . booster pump failing to start
C . booster pump being lined up in the wrong direction
D . ship's pump speeding u
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Through a （） pump, the liquid is transferred from the suction to the discharge by the mechanical variation of the volume of a chamber or chambers.
A . positive displacement
B . ejector
C . centrifugal
D . air compressor
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A centrifuge of which the bowl is arranged as the upper and lower parts separate discharges the sludge（）
A . by opening the separator manually
B . by separating the lower part from the upper part automatically
C . by separating the upper part from the lower part automatically
D . continuously
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Is there a table for , please? （） please. Is the one near the backdoor OK?
A . Take your time
B . This way
C . You are welcome
D . After you
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A vessel sailing through the specific special areas may discharge or dispose of （）.
A . incinerated ash at anytime
B . fairly dense material that will sink, i√emetal cans or glass bottles at anytime
C . victual waste when at least 12 nautical miles from shore
D . absolutely no garbage at anytime
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The discharge side of every fire pump must be equipped with a（）.
A . gate valve
B . pressure gauge
C . check valve
D . strainer
-
Above-normal tides near the center of a hurricane maybe caused by the（）.
A . high barometric presure
B . jet stream
C . storm surge
D . torrential rai
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The ocean bottom （a region nearly 2.5 times greater than the total land area of the Earth)
The ocean bottom (a region nearly 2.5 times greater than the total land area of the Earth) is a vast frontier that even today is largely unexplored and uncharted. Until about a century ago, the deep-ocean floor was completely inaccessible, hidden beneath waters averaging over 36,000 meters deep. Totally without light and subjected to intense pressures hundreds of times greater than at the Earth's surface, the deep-ocean bottom is a hostile environment to humans, in some ways as forbid- ding and remote as the void of outer space.
Although researchers have taken samples of deep-ocean rocks and sediments for over a century, the first detailed global investigation of the ocean bottom did not actually start until 1968, with the beginning of the National Science Foundation's Deep Sea Drilling Project (DSDP). Using techniques first developed for the offshore oil and gas industry, the DSDP's drill ship, the Glomar Challenger, was able to maintain a steady position on the ocean's surface and drill in very deep waters, extracting samples of sediments and rocks from the ocean floor.
The Glomar Challenger completed 96 voyages in a 15-year research program that ended in November 1983, During this time, the vessel logged 600,000 kilometers and took almost 20,000 core samples of seabed sediments and rocks at 624 drilling sites around the world. The Glomar Challenger's core samples have allowed geologists to reconstruct what the planet looked like hundreds of millions of years ago and to calculate what it will probably look like millions of years in the future. Today, largely on the strength of evidence gathered during the Glomar Challenger's voyages, nearly all earth scientists agree on the theories of plate tectonics and continental drift that explain many of the geological processes that shape the Earth.
The cores of sediment drilled by the Glomar Challenger have also yielded information critical to understand the world's past climates. Deep-ocean sediments provide a climatic record tracing back hundreds of millions of years, because they are largely isolated from the mechanical erosion and the intense chemical and biological activies that rapidly destroy much land-based evidence of past climates. This record has already provided insights into the patterns and causes of past climatic change information that may be used to predict future climates.
The author compare the ocean bottom to a "frontier" in paragraph 1 because it______.
A．is a quite promising place.
B．is out of the understanding of many scientists.
C．attracts courageous explorers.
D．is an unknown research area to the scientists.
