体育课上，老师要测量一下每位同学从一楼登上三楼的功率．为此，需要测量一些物理量，如：①三楼地面到一楼地面的高度；②从一楼到达三楼所用的时间；③每个同学的质量或体重； ④一楼到三楼楼梯的长度．上述物理量中必须测量的是____ ．

纪录片《我在故宫修文物》第一次完整呈现世界顶级的中国文物修复过程和技术，展现文物的原始状态和收藏状态。该片总策划、故宫博物院院长单霁翔指出：“文物修复切忌‘创造性修复’，科班出身的新晋学徒们要摒弃艺术教育所赋予的创造性思维方式，恪守‘修旧如旧’的准则。”这说明文物修复要（    ）

①继承传统文化财富，满足人民的精神需求

②丰富传统文化内涵，展现传统文化的魅力

③批判继承历史文化，展现文化的源远流长

④提高文物保护能力，保存民族的历史文脉

    While  Tom and Mary were on holiday at the seaside, they enjoyed 1seagulls(海鸥). They learned a lot about these2birds.
They will often come close to you on the beach when you are eating something. If you3a piece of bread to them, they will take it away quickly.
    Seagulls swim well, but they do not often dive(潜水)for fish. They are4good at flying with their wings(翅膀)。When a seagulls is flying, It puts its legs5its body. Tom often watched them6close to the ground because he like the way they7the air with their wings and put8their feet before they touched the ground. Mary liked to see them flying over the9smoothly(熟练的) and quietly without their wings moving, 10she said she didn't like the noise they made. 

把肯定句改成双重否定句

①这是一个阳光明媚的中午。②我对同学们的勇敢精神，从心底里感到无限的敬佩。