肺阴亏损致咳的痰质为（）。
A.痰稀色白
B.痰稠色黄
C.干咳少痰，或痰少成丝状
D.干咳少痰，或痰中带血丝
E.咳痰量多色白
参考答案：D
5，6，7三个数的平均数是______．
______ money is important, many teenagers say they want to do jobs they enjoy.
A．Because
B．Unless
C．If
D．Although
