释放驱动气体的机构是（）
A.气动球阀
B.定压动作机构
C.单向阀
D.电磁阀
参考答案：D
from other continents for millions of years,Australia has many plants and animals not found in
any other country in the world.[ ]
A.Being separated
B.Having separated
C.Having been separated
D.To be separated
A．电能
B．电流
C．电压
D．电功率
