英语首字母填空In Britain,cars,buses and bikes must keep to the l(ef

英语首字母填空
In Britain,cars,buses and bikes must keep to the l(eft) side of the street.If a person wants to c(ross) a street,he must stop and either look at t(raffic) lights or look at both ways of the street.And i( ) of looking left first,as we do in China ,they look right first.
To go round in London,visitors must l( ) to use buses and underground trains.