2 . In the past twelve months the research members ______ the effectiveness of many materials in a home building . A . had studied B . would study C . studied D . have studied请说明一下，谢

转为第三人称We have three lessons in the morning.My favourite lesson is art.At eleven oclock,we have a breakand I talk to my friends.They go to the playground and play football,but I dont like football!we have at dining hall ai half past twel in the past造句 Memory in the past in the past two in the past翻译 ：in the past century in the past long in the past few Trapped in the past in the past 用in the past造句 In the past 是什么时态 in the past.的同义词 in the past few years in the past的用法 In the past people是什么意思 翻译：in the past 急 See you in the past