若发动机温度过高,应怠速运转()分钟。
A.1~2
B.2~3
C.3~4
参考答案:A
It is such ________ honour to take part in ________ celebration,so how could I make any mistakes?
A.an;/
B.the;the
C.an;the
D./;the
若单项式-3xa-by5与单项式2xy5a+b的和仍是单项式,则a+b=( )。