1.__Have_____you ever__forgotten______（forget)your mom's birthday?
2.By the end of last spring,we__had planted_____（plant）two thousand trees on that hill
3.Linda told me she_had been______(be）to hong kong twice
4.I hurried home after i___had finished___(finish） all my work
5.___What's___ ___happened___ __to____（怎么啦）you?