--Have you decided where to go for your summer vacation? --Not yet. We_________ go to Mount Lu. It is a good place for vacation.
It was raining ________when we were on our way home.
Jack’s grandfather ________for more than twenty years.
They went on working ________the heavy rain.
--- Have you seen the film Titanic? ---No , but I ________.
---- Is Ann knocking at the door? --- No, it ______ be Ann. She has gone to Beijing.