B

    Scientists say life will be very different in 2050.

    First, there will be no TV channels (频道) in 2050. People will choose a program (节目) from a computer and watch it on TV. In 2050, we will get information from the computers only.

    Second, water will be a big problem in 2050. In many places, people won't have water to drink.

    Third, cars will use new and clean fuels (燃料) and they will go very fast. There will be a computer in every car. And the computers will control the cars and there won't be any accidents (事故).

小明看电视时，看到电视广告上说变形金刚真棒，马上就订购。 （   ）

下列关于黄土高原退耕的讨论，不正确的是（　　）

若点P（1，1）为圆${\left(x-3\right)}^2+y^2=9$的弦MN的中点，则弦MN所在直线的方程为（   ）