急性风湿热患儿,心尖区听到吹风样收缩期杂音,常见原因为()
A.左房室瓣狭窄
B.心脏炎
C.无临床意义
D.同时存在先天性心脏病
E.与发热有关
参考答案:B
Tim was so tired this morning. It was difficult to _________ of bed.
A.get over
B.get up
C.get out
D.get away
()不是钢电弧焊时氢的危害。
A.产生气孔
B.产生白点
C.引起氢脆
D.引起热裂纹