往复压缩机的实际工作循环包括：压缩、排气、                、          四个过程。

A．Sex difference is high hunting and gathering societies and low agricultural communities.
B．Hunting and gathering societies are collectivistic and agricultural communities are individualistic.
C．Hunting and gathering societies emphasize obedience and agricultural communities emphasize self-reliance. .
D．Members of hunting and gathering societies are very sociable and members of agricultural communities are less sociable. .
E．Hunting and gathering societies emphasize sharing and members of agricultural communities emphasize concept of ownership and control.