Ⅰ.用所给单词的正确形式填空
1．When the police arrived, the thieves ________(run) away.
2. I was not sure whether I ________(meet) him before.
3．By the time he ________(get) home, his wife ________(prepare) supper.
4．Before the manager ________(finish) his words, they ________(begin) to argue at yesterday's meeting.
5．It was the first time that she ________(tour)to Tibet.
