可在胸骨左缘第3~4肋间触及收缩期震颤的疾病是()
A.肺动脉瓣狭窄
B.室间隔缺损
C.主动脉瓣狭窄
D.二尖瓣狭窄
E.动脉导管未闭
参考答案:B
There is no bridge or boat. It’s difficult for people_____the river
A. cross B.to cross C. crossing
I was so tired this morning that I couldn't ________ early as usual. [ ]
A. get up
B. get on
C. get off
D. give up