C Choose the correct item. e.g. Never carry a second person........ your bike. 19 Be careful when you cross the street ........ foot. 20 When you travel ........ a bus, don't lean out of the window. 21 Always wear a seat belt when you travel ........ a car. 22 It's safe to travel ........ train. 23 It isn't dangerous to travel ........ plane 24 The library isn't far so I go ........ bike.