【单选题】组合夹具是由一套预先制造好的( )组成的专用工具。
【单选题】下列哪一种情况引起总需求曲线向右方移动?( )。
【单选题】组合夹具是由一套预先制造好的标准元件组合而成,这些元件具有各种不同形状、尺寸和规格,并且有较好的()和较高的精度。
【判断题】( ) 组合夹具是由一套预先制造好的标准元件组装而成的新颖夹具。
【单选题】We can learn from the last paragraph that .
A.
it is necessary to obtain as much information as possible
B.
people should make the best use of the information
C.
we should realize the importance of accumulating information
D.
it is of vital importance to acquire needed information efficiently
【简答题】From the refined oil we obtain important products, such as gasoline, ______ , detergents,______, ______ , and perfumes.
【单选题】其他条件不变时,下列哪一种情况会引起总需求曲线向右上方移动( )
【单选题】Which system should be supplied to obtain the best efficiency and lowest emissions?
A.
Lean combustion principle
C.
Electrical control system
D.
Electronic control system
【单选题】国防法规规定的 公民的国防义务有:( )的义务、接受国防教育的义务、保护国防设施的义务、( )的义务、支持国防建设协助军事活动的义务。