【简答题】目前,山西大部分农村的饮用水主要还是地下水.常期饮用硬度大的地下水不利于人体健康. (1)造成水硬度增大的原因是______,检验某地下水是硬水还是软水,可使用______; (2)水的碱性太强也不适合饮用.测定地下水的酸碱度可用______. (3)净化天然水,可通过______除去水中不溶性杂质,同时还需要消毒.X是一种新型的自来水消毒剂,工业上制取x的化学方程式为:Cl 2 +2NaClO ...
【简答题】A listener has written from China for advice about how to lose weight. Michael in Shanghai says he is 26 and has battled obesity for most of his life. Obesity , a severe weight problem, is a complex c...
【判断题】从文化学的角度,民俗与旅游都是一种文化形态。
【简答题】China has a written history of over 5,000 years of _________________.
【单选题】observation/ obzə:’veiʃən/