化简下列各式：

（1）5ab﹣3ab+12ab；

（2）4x²y﹣2xy²﹣5xy²+2x²y；

（3）2（x²y+xy）﹣3（x²y﹣xy）﹣4x²y；

（4）a²﹣2[a²﹣（2a²﹣b）]．

--- When did the old man die ?

--- He ________a rainy winter evening.

A．passed away in

B．past away in

C．passed away on

D．past away on