After his uncle died ，the young man _____the beautiful estate with which he changed from a poor man to a wealthy noble ．

Thedestructionofthetwintowers_________shockandangerthroughouttheworld．

I don ’t think you'll change his mind ；once he ’s decided on so something he tends to _____it.

The team played hard because the championship of the state was______.

设数列 {an} 的前 n 项和为 Sn，则 {an} 等差。

(1) S n4=n 2+2n, n=1,2,3

(2) S n4=n 2+ 2n +1,n=1,2,3