题目

水是生命之源!“珍惜水、节约水、爱护水”是每个公民应尽的义务和责任。 （1） 用如图所示装置进行电解水的实验，a、b两玻璃管中收集到的气体质量比为，反应的化方程式为，该实验证明水是由组成的。 （2） 在生活中可用区分硬水和软水；生活中降低水的硬度的方法是。 （3） 净化水的操作有①过滤、②蒸馏、③静置沉淀等多种，其中净化程度最高的操作是（填序号）。净水器中经常使用活性炭，主要利用活性炭的性。 用括号中词的适当形式填空【1】It’s __________________ (danger) to play football in the street .【2】He became __________________(interest) in science when he was ten years old.【3】I think it’s ___________(easy ) to learn English than to learn Chinese.【4】 He looked __________________(sad) at the broken toy car.【5】Would you like _____________(join) the trip to the Tai San Park ? It’s very interesting .【6】The teacher made us _____________________(clean) the classroom【7】Many wild animals’____(live) areas are becoming farmlands.【8】Look! The police _________________ (hunt) for the lost dog in the forest.【9】There __________________ (be) a wonderful basketball match this weekend, won’t there?【10】The policeman told the children __________________ (not play) football in the street.