问题

From this simple concept ________ that has caused a great change in farming

A:has developed a technique
B:has a technique developed
C:a technique has developed
D:developed as a technique has

正确答案是：

同类题型

We students can _______ food and old clothes to the homeless people, and the teachers can __________ learning skills for the poor children.

He is a teacher. He has been a teacher ____ 1990.

Why _____ to bed early

good timewe had at the party last night!— Yes． It was excitingparty that I would never forget it．

Would you please pass me today’s newspaper —_______