破裂后不易形成血肿（）
A.颈内后交通动脉瘤
B.前交通动脉瘤
C.大脑后动脉动脉瘤
D.大脑中动脉动脉瘤
E.椎基底动脉动脉瘤
参考答案：E
_____ favorite subject is biology. [ ]
A. His
B. He’s
C. He
D. Him
什么是附着作用和附着力？
