与口鼻腔相通或在口腔内手术的创口属于（）
A.无菌创口
B.污染创口
C.感染创口
D.一期愈合创口
E.延期愈合创口
参考答案：B
It was along the Mississippi River _______ Mark Twain spent much of his childhood.
A．how
B．which
C．that
D．where
心源性脑栓塞时，栓塞多发生在
A．大脑前动脉B．大脑中动脉C．椎动脉D．大脑后动脉E．基底动脉
