LTE同步过程中，无线帧同步是通过什么信号来实现的（）
A.PBCH
B.PSS
C.SSS
D.RS
参考答案：B, C
肾血管平滑肌脂肪瘤与肾癌的主要鉴别点是
A．瘤内有无脂肪
B．肿瘤部位
C．肿瘤密度的均匀性
D．肿瘤边缘是否清楚
E．肿瘤有无强化
He to get back yesterday, but he didn't. [ ]
A. expected
B. was expected
C. expecting
D. was expecting
