音高的变化维度，据有关资料，可传递的最大值为（）
A.2.3比特
B.2.7比特
C.2.5比特
D.3.1比特
参考答案：D
At the meeting they discussed three different _______ to the study of mathematics.
A．approaches
B．means
C．methods
D．ways
－Mike, why are you watching TV again?
－I _________ my homework.
A. finish B. finished C. have finished
