一、用所给词的适当形式填空。
1.Our teachers always guide us __________(listen) much more carefully in class.
2.Some citizens waited for the workers to repair their broken water pipes quite long, and they became ________ (patient).
3.I was looking for the pen which I ________(buy)yesterday when you called me.
4.China ______(send) up several Shenzhou manned spacecrafts into space since 2003.
