1. In/ 1970s, skateboarding suddenly/ become very popular. 2. At first, skateboarders/ move slowly/ flat, smooth areas. 3. Then they/ begin/ ride quickly. This/ be called freestyle skateboarding. 4. Soon they/ be skateboarding skillfully up ramps/ doing tricks in the air. 5. This/ be called ramp skateboarding. Then they/ start skateboarding/ doing tricks/ the street. 6. This/ be street-style skateboarding - a combination of freestyle/ ramp. 7. For this, the skateboarders/ need protective clothing/ as knee and elbow pads/ helmets. This/ allow them/ skateboard safely. 8. Today skateboarding is still/ very popular sport, and there/ are lots of competitions.