根据情景，用所给动词的正确形式填空。
WhatwereBen,Jake,LucyandLilydoingonDecember31st,2011?They(1)_____(prepare)theirparty.Lucy(2)_____(buy)crisps.Lily(3)_____(organize)themusic.BenandJake(4)_____(fetch)chairsandtables.(5)_____theirparents_____(help)them?No,they(6)_____(nothelp)thembecausethey(7)_____(sit)ontheplaneontheirwaytoAustralia.
【指点迷津】
一般说来，要表示过去某个时刻或某一时段正在进行的动作，我们常用过去进行时。常和过去进行时连用的时间状语有：then,atthis/thattimeyesterday,at…lastnight,thewholemorning,from…to…lastnight等。