交感神经支配的支气管平滑肌上具有()型受体。
A.α1
B.α2
C.β1
D.β2
参考答案:D
心肌梗死时LD同工酶显著升高的是()
A.LD1
B.LD2
C.LD3
D.LD4
E.LD5
As for the influence of Internet, nowhere ( ) the results more clearly than in the US.
A.we have seen
B.we had seen
C.seen we have
D.have we seen