慢性肺源性心脏病失代偿期心功能失代偿多表现为()
A.以右心衰为主
B.以左心衰为主
C.多为全心衰
D.多为肺水肿
E.缺氧和二氧化碳潴留
参考答案:A
When you read the book, you'd better make a mark ____ you have any questions. [ ]
A. at which
B. at where
C. the place
D. where
静脉注射的优点是()、()、()、()。