A hard-working man__ _______become a great scientist, but a great scientist__________be a hard-working man.
When the firemen arrived, the fire had been_______.
--When are you going to tell the bad news to Jim?--_______ he comes back.
–Do you like basketball or soccer?–_______. Soccer is too hard for me.
Qomolangma is _______ high _______ very few people can climb up to the top of it.
–Whose is this purple scarf?–It _______ be Mary’s. She always wears a purple scarf like this.