用on.因为电视是看屏幕，也就是在表面看，而不是在电视里边看，钻不进电视里边去看，所以是on
Digital television has been around for some time now.
数字电视已经面市一段时间了。
I'd like to work on Tv
我希望从事电视广播事业。
Does Tv have an effect on children's behaviour?
电视对孩子的行为有影响吗？
Please turn the Tv off before you go to bed.
睡觉前请关上电视。
