Towards evening, the patient opened his mouth as if _____ something to his son.
______, they would certainly come and help us.
-How long ______ each other before they ______ married?--For about a year.
Smith ______ a book about China last year, but I don't know whether he has finished it.
I paid him $ 50 for the painting , but its true ___ must be least $500.
Any student ___ will be disqualitified from the exam.