质量数据统计指标的子样平均值表示为()。
A.A
B.B
C.C
D.D
参考答案:A
若a、b、c均为质数,如果(a+b)(b+c)=342,那么b=( )
A.31
B.19
C.2
D.7
With many major economic problems_______ to be addressed, there is no point _______ the growth rate of this year now.
A.remaining ; predicting
B.remaining ; to predict
C.remained ; predicting
D.remained ; to predict