Complete the text using the words. There are two extra words.

Skateboarding has become a very popular ... . All a person needs to enjoy this sport is a skateboard, good ... , and some ... . It is a good idea to use safety helmets and kneepads because even the best skateboarders ... fall. To begin skateboarding, put one foot on the skateboard and push forward with the other ... . When you get moving fast enough put both ... on the ... . You keep your balance by moving your arms and ... . The more you practise, the easier it ... .