他们需要多加练习,因此他们在两个月前就忙这个事了!they need to practise a lot ——they started ——
问题描述：
他们需要多加练习,因此他们在两个月前就忙这个事了!they need to practise a lot ——they started ——
they need to practise a lot ——they started —— —— it two month ago
答
they need to practise a lot so they started busy in it two nonth ago!为什么呢？so，是因此啊。busy in 是忙于