A、The drivers must go at more than thirty miles an hour. B、The ears should go at exactly thirty miles an hour. C、The drivers mus

These are some of the signs that you see on the roads of Great Britain.
    Number one is a sign with the number thirty on it. When drivers see this sign they must not go at more than thirty miles an hour. We see this sign when we got to pints of the country where there are many houses and other buildings, for example, when we are getting near a town. Thirty miles an hour is the speed limit. Number two is the sign for the end of the speed limit. We are out of the town now and may go at more than thirty miles an hour.
    Number three is a sign that we are near a crossroads that is a place where two roads cross. We must drive carefully.
    Number four is a sign that there is a bend in the road. Again we must drive slowly and carefully.
    Number five is a sign that there is another mad coming in from the fight. This road joins our mad. There is a road junction at this place.
    Number six is a sign that there is a hill and number seven is a sign that the mad gets narrow. Drivers must go slowly and carefully.
    Number eight shows us a gate. There is a level crossing. This is a place where a railway crosses the road. The road and the railway are at the same level. There is no bridge. A level crossing is a dangerous place. Careful drivers stop or go very slowly. Is the gate across the road open or shut? Is there a train coming?
    Number nine has the word "school" on it. This is a sign that there is a school at the side of the street or road. Perhaps. there are children going to school or leaving school. So drivers must look carefully and go slowly until they are past the school building.
    Number ten is a sign with the letter P on it. The letter P is for "Parking". A parking place is a place where drivers may leave their ears. If the driver of a car wants to leave his car and go to the shops, he looks for this sign. Then he knows that he may leave his ear there.