Timoteo Apaza，a 46-year-old （1） ______ ，works as a human traffic signal．Holding a large round （2） ______ which is red on one side and green on the other，he stands on the bend to （3） ______ the traffic without pay．Sometimes，（4） ______ give him tips．Many people wonder why he does it．
As is known，La Paz is the highest capital in the world．Because of its high altitude，（5） ______ and communication are quite hard there．Many roads are in bad（6） ______ ，which leads to frequent accidents．Once，he drove a lorry going down the road that is so dangerous and （7） ______ 300meters down the mountain at a（8） ______ ．Fortunately，he （9） ______ it．Then，one night，he was called out to help people out of a （10） ______ bus at the Devil's Bend，which finally made him decide to help others and take up this job．