来源于茜草科的一组药材是（）
A.巴戟天与大戟
B.栀子与女贞子
C.钩藤与棕儿茶
D.栀子与黑儿茶
E.大戟与黑儿茶
参考答案：C
Proper timing of fiscal policy is important if the government is to:（）
A. generating revenues from taxes and sales equal to its expenditures.
B. stimulate economic activity during a recession and restrain the economy during an inflationary boom.
C. increasing the supply of loanable funds needed to place downward pressure on the real rate of interest.
用E5015焊条焊接时，焊机应选用（）。
A.BX3-300
B.BX-330
C.MZ-1000
D.ZXG-300
