为了给四辊送好的燃料，对辊生产的产品粒度应（）。
A．＜25mm
B．＜40mm
C．＜3mm
参考答案：A
. ______ understanding the challenges faced by the world’s poorest people can we expect a new future
free of extreme poverty and hunger.
A．On
B．Through
C．Only
D．Only by
从业人员数是指全年从业人数之和。（）
