I don't know why they had the light ---(burn 适当形式加原因)all day long

I don't know why they had the light ---(burn 适当形式加原因)all day long
I don't know why they had the light ---(burn 适当形式加原因)all day long

I don't know why they had the light ---(burn 适当形式加原因)all day long
burning,因为后面all day long这个时间状语,是整天都,意思是我不明白他们为什么要把灯亮一整晚,had sth doing,让什么一直处于什么状态