单项选择题

比例流量型换向阀在控制流量的同时可以________使输出流量与电信号成正比。 A.
在比例换向阀前串联定差减压阀 B.
在比例换向阀前并联定差溢流阀 C.
检测流量并反馈信号 D.
其他选项都对

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多项选择题

下列属于金属龙骨组成的是（）。
A、吊筋
B、横撑龙骨
C、主龙骨
D、次龙骨

单项选择题

Please Listen to the following TED talk and answer the questions followed.
(8分-8分29秒）
To argue against the claim that the Sun is the main cause of climate change held by climate change deniers, the speaker argues the followings EXCEPT

A．The measured energy imbalance occurred during the deepest solar minimum in the record, when the Sun's energy reaching Earth was least
B．Yet, there was more energy coming in than going out
C．This shows that the effect of the Sun's variations on climate is overwhelmed by the increasing greenhouse gasses, mainly from burning fossil fuels
D．The deep ocean is also gaining heat at a smaller rate, and energy is going into the net melting of ice all around the planet