沙丁胺醇与异丙肾上腺素比较,优点是______。
A.对β2受体的选择性高
B.平喘作用维持时间长
C.心悸的副作用少见
D.口服有效
E.可治疗心原性哮喘
参考答案:A,B,C,D
用括号内所给单词的适当形式填空
小题1:December is the ________(twelve)month of a year.
小题2:Lily always helps her mother clean the house. She is very______(help).
小题3:He sits between you and ______(I).
小题4:It’s one of the most famous ______(beach)in the world.
小题5:The police finally found the ______(rob) names and addresses.
三极管的三个电极用ebc表示e—发射极b—()c—集电极