---Peter , where did you guys go for the summer vacation?----We________ busy with our work for months, so we went to the beach to relax ourselves.
The classroom is so dirty. _________ we clean it?
Was it in the village___ we used to live in____ the accident happened ?
Over the past decades, sea ice _____ in the Arctic as a result of global warming.
After some time in the dark cave, our eyes slowly _____ the dark.
Seldom out time to watch TV on Sunday.