临床上85%~90%的颅内动脉瘤位于前循环,后循环动脉瘤常见于()
A.桥脑动脉
B.小脑后下动脉和基底动脉尖
C.小脑上动脉
D.枕动脉
E.小脑前下动脉
参考答案:B
Father together with his good friends was________to go out for a camp________it began to rain. [ ]
A. hardly; than
B. around; as
C. about; when
D. nearly; while
中药材牵牛子为()科植物裂叶牵牛、圆叶牵牛的干燥()。