Do you like travelling ?More and more students like riding bikes to travel on the road.But it may be dangerous on your trip.For your own safety ,do the following things. Wear a bike helmet and it can protect your head.Look for a helmet that fits you well.Even the best,most expensive helmet won't protect you if it doesn't fit. Wear the right clothes.They can make you feel better.And they can also protect you.Bright-colored clothes help people see you clearly-even in the daytime.Don't wear dark-colored clothes like black or brown while riding a bike. Keep the rules of the road while riding a bike.Always ride on the right side of the street in the same _ .Never change your direction without first looking behind you.Don't ride too closely to cars-the cars may stop and the doors open suddenly !Finally,don't wear earphones while riding a bike-you need to hear what's going on around you. When you travel by bike.you can't ride too closely to cars.Because  _  .
the cars run very fast the cars may stop suddenly the men on the cars may open their doors suddenly both B and C