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.
答案：(C) Since
Since 在此是表原因的從屬連接詞「既然、因為」：正因為儲存與運送的資訊不易取得，瓶裝水未必比自來水更好。Although（雖然）語意方向相反，Despite 是介系詞須接名詞，So 引導結果不能放在句首帶出原因子句。
答對率 34%。
since 你大概只想到「自從」，而且腦中綁定現在完成式，所以看到句首的 Since 帶出一個完整子句就排除了它。其實 since 有三種身分：介系詞（since last month）、表時間的連接詞（自從）、以及表原因的連接詞「既然、因為」——本題考第三種，與 because、as 意思接近：Since you are here, let's begin.（既然你來了，我們就開始吧）。
前一句說水放太久或曝曬會滋生細菌，本句接著說消費者又無從得知這些資訊——原因層層堆疊，導出「瓶裝水未必比較好」。
Although 是讓步，方向相反；Despite 是介系詞，後面只能接名詞不能接子句；So 表結果，不能引導原因子句。
since／as／because ＋ 子句（因為）、despite ＋ 名詞（儘管）、in spite of ＋ 名詞（儘管）、an alternative to（…的替代選擇）。
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.