正常情况下，与发音和语言密切相关的口腔器官是()
A．唇
B．颊
C．舌
D．齿
E．腭
参考答案：A, C, D, E
铝块的密度是2.7×103 kg/ m3它表示的物理意义是 ，若将铝块截去1/3，剩下部分铝块的密度是 g/c m3
I was most favorably struck by the assurance with which the boy answered all my questions.
A．insurance
B．confidence
C．reluctance
D．independence
