哌唑嗪降低血压不引起心率加快的原因是
A.阻断α1而不阻断α2受体B.阻断α1受体与β受体C.阻断α2受体D.阻断α1和α2受体E.阻断β受体
参考答案:A
—What does his mother look like?
—_____. [ ]
A. She's a doctor
B. She's forty
C. She's thin
D. She works in a bank
( )由一系列符号(如文字)和数字组成,是信息处理的一项重要的基础工作。
A.信息
B.档案
C.编码
D.模型