相对数时间序列中，各指标数值之间具有( )

汽油机燃料供给系的作用是根据发动机各种不同工况的要求，将洁净的汽油或汽油和空气配制出适当浓度的混合气，按一定的...

单项选择题汽油机燃料供给系的作用是根据发动机各种不同工况的要求，将洁净的汽油或汽油和空气配制出适当浓度的混合气，按一定的时间和数量供入( )。

(), the number of private cars will increase sharply in...

单项选择题(), the number of private cars will increase sharply in the coming couple of years.
A. Undoubtedly
B. Doubtedly
C. Undoubted

We can certainly deliver high-quality education to many...

单项选择题We can certainly deliver high-quality education to many students at much()cost.
A. low
B. lowest
C. lower