船尾向前地

A gunboat in the lake from the bow, stern uniform suddenly while traveling forward and backward, the emission of a shell consists of two rounds relatively the same rate the quality of the same traction and resistance to change is the ship's momentum and velocity is what?...

一炮艇在湖面上匀速行驶突然从船头船尾同时向前和向后各发射一炮弹设两发炮弹质量相同相对地的速率相同牵引力和阻力不变则船的动量和速度的变化是怎样的？。。。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。