【单选题】___ we know, in a chemical change, energy cannot be created, ____.
A.
Which, nor can it be destoyed
B.
As, neither it can be destroyed
C.
As, neither is it able to be destoryrf
D.
What, nor is destoryed
【多选题】Water wheels are machines that use the energy of ______ to turn a wheel. The axle of the turning wheel can then power other machines to do work.
【单选题】For a (n) ___________ system, neither matter nor energy can be transferred between system and surroundings.
【多选题】按生产系统的特性划分,可将服务性运作划分为()。
【单选题】The reason why the first type of perpetual motion machine cannot be successfully manufactured is ( )
A.
energy can neither be created nor destroyed
B.
the loss of work in the actual process is unavoidable
C.
the only forms of energy transfer are heat and work
D.
not all the heat can be converted successfully
【单选题】It is never easy to identify the complexity of the negotiating subject and the priority when it comes to the agenda-making phase in international business negotiation. Some simple issues could be easi...
A.
From easy to difficult.
B.
From difficult to easy.
【单选题】__ we know, in a chemical change, energy cannot be created, ____.
A.
Which, nor can it be destroyed
B.
As, neither it can be destroyed
C.
As, neither is it able to be destroyed
D.
What, nor is destroyed
【单选题】According to the text, what can we learn about aviation fuels?
A.
Biofuels can be used as replacement for vehicles as well as planes.
B.
Neither biofuels nor coals can be used for planes.
C.
The idea of green fuel is to change solar energy into fuels.
D.
The idea of green-fuel, which is only an illusion, is challenged and doubted by scientists.