About two years ________ since the earthquake took place in Wenchuan.

---How long have you _____ this magazine ?    ---For a week.

She _______ a lot of money on clothes.

．—This math problem is too difficult. Can you show me _______, Dad?—Sure.

A big party was held in NO.18 Middle School last night, the teacher with students _____ singing and dancing happily at the party.