引起支气管平滑肌舒张的肾上腺素能受体为
A．α受体B．β1受体C．β2受体D．M受体E．N1受体
参考答案：C
Boys and girls , don't forget your report. It ____ today.[ ]
A. can't finish
B. can't be finished
C. should finish
D. should be finished
皂化值是挥发油中的（）
A.酸值加皂化值
B.皂化值减酸值
C.酸值减皂化值
D.羧酸和酚类成分总和
E.酸值与酯值之和
