我猜他们那个时候肯定在看电视 I suppose they —— —— —— TV at home at that time.
问题描述：
我猜他们那个时候肯定在看电视 I suppose they —— —— —— TV at home at that time.
答
I suppose they （must）（be）（watching）TV at home at that time.
mush be doing这里表示肯定的推测,“一定在做什么”.
【公益慈善翻译团】真诚为您解答!