肺痨的外在致病因素是（）
A．燥邪
B．瘵虫
C．痰浊
D．瘀血
E．水饮
参考答案：B
读一读，排顺序。
( ) I like winter best. We play in the snow.
( ) Which season do you like best?
( ) Why?
( ) Halloween and Thanksgiving!
( ) Winter is good, but fall is my favorite season.
对具有常规现金流量的投资方案，其财务净现值是关于折现率的( )函数。
A．递减B．递增C．先递减后递增D．先递增后递减
