The reason for his success is ______ he worked very hard.
No problem lasts forever. Storms always __________ the sun.
—What's the matter with her car?—It looks __________ the engine couldn't work.
He studied hard,__________ the exam.
The living room is clean and tidy, with adining table already __________ for ameal to be cooked.
—Do you think it's a good idea to make friends with your students?—__________,I do. I think it's agreat idea.