Since you are ill, you ______ attend the meeting.
---Remember this, children. ____careful you are,____mistakes you will make.---We know,Mr. Li.
—_________do you study for a test? —By_________to tapes.
—Do you know _____ ? I'm going to see him. —Sorry, I don't know.
Let’s ask Mr. Wang for ________ about the earthquake.
If you don’t know a word, you must in a dictionary.