根据下列句子及所给汉语注释，写出空缺处各单词的正确形式，每空只写一词。
There are more than two _________(千) students in our school.
He didn’t go to bed ____________(直到)his father returned home.
My mother was busy cooking in the ____________(厨房).
It is ______________(可能) for us to finish the work in such a short time .
Tonny has been ______________(收集) seashells for four years..