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____ ．

阅读下面材料， 在空白处填入适当的内容(1个单词)或括号内单词的正确形式。

    Brighton is the____ (health)city in Britain with the highest level of personal trainers, yoga clubs and health food stores, according to a survey related on Friday.

    The survey, ____ looks at 19 statistics covering health, ____ （fit）and environment, says Brighton has the highest number of residents ____ (eat) at least five kinds of fruit and vegetables a day.

    The survey, ____ (conduct) for the Sky Travel channel, has compared 15 cities across the UK. It says Brighton residents live ____ an average age of 78 years old. They are twice as likely ____ (walk) or cycle to work as the people living in other parts of Britain.

    In ____ （compare）with the national average, Brighton has nearly a third more health food stores and personal trainers than____ in any other city in Britain. It has twice many yoga clubs, and the level of fat residents is below the national average.

    Meanwhile, ____ survey also finds that Brighton residents have the best levels of cholesterol (胆固醇) and blood pressure in Britain.

阴影部分面积是____平方米。