单项选择题
Such changes can alter the social structure,（）people to move.
A.leading B.which led C.leads D.which leading
单项选择题 Cycling is a good exercise.（）, it doesn't pollute the air.
单项选择题 They were asked to avoid（）any water which had not been boiled.
单项选择题 These radio and TV networks have（）in the UK
