苯妥英钠抗癫痫作用主要原理是（ ）
A．激动GABA受体
B．稳定神经细胞膜
C．抑制脊髓神经元
D．肌肉松弛
E．广泛抑制中枢
参考答案：E
Would you mind ______ the stereo? I can't hear what he is saying. [ ]
A. turn off
B. turn down
C. turning off
D. turning down
Our school is having a sports meeting. Someone _____ here already. [ ]
A. arrived
B. have arrived
C. has arrived
