主动脉内膜撕裂容易发生在()
A.主动脉峡部
B.胸主动脉
C.升主动脉
D.降主动脉
E.主动脉弓
参考答案:A
Play, often seen as _____ activity for kids, is still important in _____ development of teenagers. [ ]
A. the; the
B. an; the
C. an; 不填
D. the; 不填
【16】 权限允许增加或删除关系中的属性。