The teachers encourage their students to________the problems by themselves,and in this way students can enjoy success.A.give upB.work outC.look through
— ____ do you clean the classroom? — Three times a day.
He prefers _______ to __________.
There _____ an exciting party at Mr. Wang’s this evening.
Are you free now? I have ___________ to tell you.
There is a ______ tree in our school.