发生小脑幕切迹疝时，下列哪项通过小脑幕切迹被推移至幕下：（）
A．额叶直回
B．颞叶钩回
C．中央前回
D．扣带回
参考答案：B
Tom was playing computer games all night.________he was late for class.[ ]
A. That's because
B. That's why
C. It's how
D. That's how
VHF共用系统主备自动转换时间小于（）S。
A、1
B、1.5
C、2
D、2.5
