双曲线y=-2x的图象经过点（1，m），则m=______．

III. 完形填空（Cloze）(共15小题，计15分)
阅读下面短文，掌握其大意，然后从方框内选择适当的单词或短语填空。方框内有多余的词或短语，每个词或短语限用一次。（答案写在答题纸上）
  

Many tourists nowadays walk around carrying plastic bottles of water, even in cities. The bottles seem to have become an (71)________ fashion accessory（配件）, and not only for tourists. (72)________, nowadays everyone seems to carry a bottle of water with them (73)________ they go. This fashion for being seen with bottled water, (74)________ called “designer water”, has (75)________ a massive（大量的） increase in sales over the past few years. There are now so many (76)________ brand names available in the shops that it is hard to choose.

    But why do some people prefer their water from a bottle (77)________ a tap? To start with, water forms a very important (78)________ of a healthy lifestyle. We are now advised to (79)________ two litres of water daily, (80)________ eating large quantities of fruit and vegetables. Besides this, designer water offers the promise (81)________ purity.
It is advertised as clean and (82)________, while tap water (83)________ be viewed with suspicion （怀疑）.
But is there really any difference between bottled and tap (84)________? Surprisingly, in the USA it was (85)________ that bottled water was not always as pure as most ordinary tap water.