Bottled water is mostly sold in plastic bottles and that's why it is potentially health 26 .
答案：(B) threatening
【句型】health-threatening 固定複合形容詞用法「危害健康的」；frightening（令人害怕的）、appealing（吸引人的）、promoting（促進的）都不合。
四個都是 -ing 形容詞，代進去形狀一樣。frightening 很誘人，因為「令人害怕的」和「有害的」在中文裡感覺很近；也有人挑 appealing，因為前一句才剛說很多人喜歡喝瓶裝水。
先看空格前面那個字：health。它和空格合起來是一個複合形容詞，用來形容瓶裝水，所以要找的是「對健康做了什麼」的那個字。答案在下一句：Processing the plastic can lead to the release of harmful chemical substances into the water（塑膠加工可能把有害的化學物質釋放到水裡）。harmful 直接定調——瓶裝水是危害健康的。health-threatening 就是「危害健康的」，threaten 的意思是威脅、危及。整篇的走向也很清楚：從第一句 is bottled water really any better? 開始就是在質疑瓶裝水，接下來全部在列缺點。順帶把 threatening 的用法一起記起來：threatening weather（快變天的天氣）、a threatening letter（恐嚇信），核心都是「帶來威脅」；複合形容詞 health-threatening、life-threatening（危及生命的）是常考的組合。
frightening：令人害怕的，講的是心理感受；瓶裝水的問題是實質傷害身體，不是嚇人。appealing：吸引人的，方向完全相反，整段在講它的壞處。promoting：促進的，health-promoting 是「促進健康的」，語意剛好相反。
health-threatening（危害健康的）、life-threatening（危及生命的）、health-promoting（促進健康的）、lead to（導致）、harmful substances（有害物質）、be exposed to（暴露於…）。
Many people like to drink bottled water because they feel that tap water may not be safe, but is bottled water really any better? Bottled water is mostly sold in plastic bottles and that's why it is potentially health 26 . Processing the plastic can lead to the release of harmful chemical substances into the water contained in the bottles. The chemicals can be absorbed into the body and 27 physical discomfort, such as stomach cramps and diarrhea. Health risks can also result from inappropriate storage of bottled water. Bacteria can multiply if the water is kept on the shelves for too long or if it is exposed to heat or direct sunlight. 28 the information on storage and shipment is not always readily available to consumers, bottled water may not be a better alternative to tap water.
Besides these 29 issues, bottled water has other disadvantages. It contributes to global warming. An estimated 2.5 million tons of carbon dioxide were generated in 2006 by the production of plastic for bottled water. In addition, bottled water produces an incredible amount of solid 30 . According to one research, 90 of the bottles used are not recycled and lie for ages in landfills.