对于支气管扩张,咯血的手术禁忌症是()。
A.病变范围局限单侧
B.病变小于两个肺叶
C.反复咯血
D.心肺功能差
E.反复继发扩张部位重度感染者
参考答案:D
The moonlight was quite bright, and about fifteen yards up the road there was a deep _______ thrown by a tree.
A.shade
B.shadow
C.shelter
D.reflection
在实数范围内因式分x2-3x+1=______.