Red man means you mustnt cross the road now.Green man means you can cross the road now.must 必须mustnt 禁止Green man, green man, go, go, go. Yellow man, yellow man, wait, wait, wait. Red man, red man, stop, stop, stop. Are there any busy roads in your city?Which road is the busiest in your city?Why?traffic jamIts very difficult to cross the roads safely.
