Adding edges to ice skates was invented by the Dutch in the 13th or 14th century. These ice skates were made of steel, with sharpened edges on the bottom to aid movement. The construction of modern ice skates has stayed largely the same. The only other major change in ice skate design came soon after. Around the same time period as steel edges were added to ice skates, another Dutchman, a table maker’s apprentice, experimented with the height to width ratio of the metal blade of the ice skates, producing a design that remains almost unaltered to this day. The user of the skates no longer needed to use sticks for propulsion, and movement on skates was now given more freedom and stability.

It's a beautiful day — the sun is shining, the birds are chirping. What could be more perfect than a bike ride? Bike riding is a lot of fun, but accidents happen. Every year, about 300,000 kids go to the emergency department because of bike injuries.

Wearing bright clothes and putting reflectors on your bike also can help you stay safe. It helps other people on the road see you. And if they see you, that means they're less likely to run into you.
You'll also want to make sure that nothing will get caught in your bike chain, such as loose pant legs, backpack straps, or shoelaces. Wear the right shoes — sneakers — when you bike. Sandals, flip-flops, shoes with heels, and cleats won't help you grip the pedals. And never go riding barefoot! Riding gloves may help you grip the handlebars — and make you look like a professional!