题目

下图是实验室常用的实验装置，请回答有关问题：                 A             B              C            D         E （1）装置C由导管、            和            （填仪器的名称）组成。装置A中试管口应放一团棉花,其作用是___________________________________________。 （2）用加热KMnO4的方法制取氧气，选用的发生和收集装置是            （填装置序号，下同）；装入药品前，必须进行的第一步操作是________用所给动词的适当时态填空【1】We _______（plant）trees in spring every year. These days we _______（plant）trees on eachside of the street.【2】Wang Ying _______（study）at Qinghua University. She _______（do）well in her lessons.【3】My brother _______（join）the PLA in 2003.【4】What ____ you usually ____（do）on weekends? I usually ____（go）to see a film.【5】They _______（have）sports on the playground now. _______ they _______（have）sports every day?【6】How often ____the boy ____（watch）TV? He _____（watch）TV three times a week.【7】The students _______（have）an English test every two months. Sam _______（not do）well last time. He _______（do）better next time.