热力除氧是根据( )的基本原理。
A.阿基米德定律和道尔顿定律 B.道尔顿定律和亨利定律C.道尔顿定律和自控定律 D.自动定律和阿基米德定律
参考答案:B
All these people are now making an active to improve our environment.
A.effect
B.effort
C.decision
D.affect
Jim lives in a place _____Gum Tree.[ ]
A.calls
B.calling
C.called
D.to call