If you want to look around ,try the Londin street pavement for the best value and for the best show

题目

If you want to look around ,try the Londin street pavement for the best value and for the best show in town-Londoners going about their daily business.这个句子中-Londoners going about their daily business做什么成分,为什么用going about而不用is going about

答案

If you want to look around （从句）,（主句我谓语是try）try the London street pavement for the best value and for the best show in town-Londoners going（这个是非谓语做独立结构） about their daily busin...