aim is to inform the viewers that cigarette advertisements on TV are illegal,_______

Where did you get to know her?—-It was on the farm______ we worked

Professor Smith will come here to give a speech.All the preparations must be________before 5 o’clock.

Just like fingerprints, each person’s DNA is ________unless he has a twin.

MrWang was caught in a snowstorm yesterday—I have known that, and ______ his new car was completely destroyed