—Shall we go to the Great Wall on National Day?—It’s a great idea we don’t have enough mo

问题补充：

—Shall we go to the Great Wall on National Day?

—It’s a great idea ，we don’t have enough money．

A. and

B. but

C. or

D. then

答案：

A. and

(答案→)B. but

C. or

D. then

解析：四个选项分别表示并列关系、转折关系、选择关系和先后关系，根据题意B为最佳答案，好主意，但是我没有足够的钱。