提示右心室肥大的体征有()
A.颈静脉怒张、肝颈静脉回流征阳性
B.心脏相对浊音界缩小或叩不出
C.心尖搏动左下移位
D.肺动脉瓣区第二心音亢进
E.剑突下可见心脏搏动
参考答案:E
More and more people will have fun _____ English. [ ]
A. learn
B. learns
C. to learn
D. learning
简述氢站安全注意事项。