设计合同( )生效。
A．中标通知到达设计人时
B．双方当事人签字盖章时
C．发包人支付定金后
D．主管部门登记后
参考答案：C
— I'll tell Mary about our changes tomorrow.
— What? You ______ her yesterday. [ ]
A. ought to tell
B. must have told
C. might have told
D. should have told
试运用提高成果分布的理论阐述提高经济不发达地区农民成果分布的对策？
