能够实现“收回用户U4对学生表(STUD)中学号(XH)的修改权”的SQL语句是______。
参考答案:REVOKE UPDATE(XH)ON STUD FROMU4
When Jane began to take swimming lessons, her main _____ was the fear of water.
A.evidence
B.crisis
C.obstacle
D.danger
初始附着时eNB收到UE随机接入请求消息会建立()无线承载。