在GSM的Um接口中采用的射频调制方式是：（）
A.GMSK
B.FSK
C.QPSK
D.PCM
参考答案：A
Max has a good sense of humour. We never feel ________ when he is with us. [ ]
A. bored
B. happy
C. interesting
D. funny
简述班级授课制的优点。
