舌位后、半高、唇不圆的元音韵母是（）
A、e
B、o
C、a
D、i
参考答案：A
My teacher gave me much ________ on how to study English well when I had some trouble.
A．advice
B．question
C．suggestion
D．problem
1610多串口卡扩展的串口有（）。
A.1个
B.2个
C.3个
D.4个
