The radiation amount of a mobile phone for two half-hour periods per day is equal to ___ to an X-ray for ten seconds.

如图所示为足球球门，球门宽为L，一个球员在球门中心正前方距离球门s处高高跃起，将足球顶入球门的左下方死角（图中P点），球员顶球点的高度为h，足球做平抛运动（足球可看成质点，忽略空气阻力），则（   ）

    There once lived in China a very foolish king and queen. One day the queen had a baby daughter. When they saw their baby, they both cried out, “My goodness! How small it is! It's hairless and toothless! It's a monster!” They sent for all the doctors in the country and ordered them to prepare some medicine for her.
   “When she drinks your medicine, she must grow to the right size and have hair and teeth,” the king said, “If you don't do this, you'll have a beating.”
      The doctors thought it impossible, but they dared not say anything against the king's order. Just then and old doctor stepped forward. “Oh, we shall certainly obey your order,” he said, “but it takes time. We have to dig a mineral from the KunLun Mountains when the snow melts for the second time. The snow melts on those mountains only once in six years. we need twelve years.”
    At last the king agreed and the doctors took away the little princess. On her twelfth birthday, they brought her back to her parents with long black hair and beautiful teeth. The king and queen were very happy and gave the doctors expensive presents.

用两种不同的方法化简：（﹣3m﹣n）（3m+n）+n（3m+n）

如图，若Ω是长方体ABCD﹣A₁B₁C₁D₁被平面EFGH截去几何体EFGHB₁C₁后得到的几何体，其中E为线段A₁B₁上异于B₁的点，F为线段BB₁上异于B₁的点，且EH∥A₁D₁，则下列结论中不正确的是（   ）