答案:B
-The problem wasn't difficult for him,was it ?
-______. He should have been given a more difficult one. [ ]
A. No,it was
B. Yes,it was
C. Yes,it wasn't
D. No,it wasn't
项目产品的市场需求预测所使用的主要方法有时间序列预测方法、回归预测方法和()
A.德尔菲预测方法
B.指数预测方法
C.类比预测方法
D.调查法