The doctor told me to take the medicine .
Each of us, ____old or young,is a valuable member of society.
If a computer crashes,you will lose the file you _____ on unless you save it regularly.
There you can see beautiful tall buildings on _____side of the square.
Only when you stay and live with___ local people for a period of time will you have ____better understanding of life here.
—Shall I lock the lab now before I go home? —______.I’ll check it myself later.