Match the words on the left (1-10) with their definitions on the right (a-j). 1) a baby-sitter a) your first language 2) a traffic jam b) money you pay on your salary 3) a box office c) an office where you buy tickets for trains 4) mother tongue d) an office where you buy tickets for cinemas 5) income tax e) a person who patrols streets to make sure you are not parked in the wrong place illegally 6) handcuffs f) a knife for opening tins 7) greenhouse effect g) a person who looks after children when their parents are out 8) ticket office h) a long line of cars which move slowly because the road is busy 9) a traffic warden i) it is caused by hair sprays and old fridges 10) a tin opener j) every policeman has them