下列装置不能达到对应实验目的是（ ）
A．
制取CO2气体
B．
证明分子是不断运动的
C．
探究燃烧的三个条件
D．
比较MnO2和Fe2O3的催化效果
A、二氧化碳的密度比空气密度大，应用向上排空气法收集，该选项中用向下排空气法来收集错误，不能达到目的，故选项正确；
B、氨水具有挥发性，氨气溶于水得到氨水，氨水呈碱性，会使酚酞变红，证明分子是不断运动的，能达到目的，故B错误；
C、白磷和水中的白磷作对比，只能得出燃烧的条件：需要与氧气接触，不能得出燃烧的三个条件，不能达到目的，故选项正确；
D．比较二氧化锰和氧化铁对过氧化氢的催化作用，需所选的过氧化氢的浓度等除催化剂种类以外的其它量都相同，否则没有可比性，能达到目的，故D错误；
故选：AC．
根据短文内容，选出5个句子填入文中空缺处，使短文内容完整正确，其中一项为多余选项。 Which university would you like to go to in the future? It’s not too early to think about it right now. Students at Hilltop School had a University Week at the end of last month.小题1: For instance, they designed a flag for a virtual(虚拟的) “University of Hilltop”. 小题2: He said he started the program to help students form their aims. “University may not be for everyone, but we want the program to help students form their aims.” He said. 小题3: Eric ,a student in Grade 8,said“University Week made me realize that university is only four years away. I should do research about where I want to go.” Paul, another student in Grade 8 said that he realized there were so many universities for him to choose. 小题4: The school also invited people to give career talks. The first talk was given by Captain Brown, a policeman. He talked about how to choose a career way. 小题5: “The program opened up the students’ eyes.” said Mr Miller.
|