正确答案: ABD
称量实验前铜丝网的质量 将实验后的铜丝网干燥、称重 将实验后的铜丝网插入AgNO3溶液中
题目:如果用本实验探究铜是不是H2O2分解的催化剂,需要对上述实验方案进行补充,其中必要的是________。
解析:ABD
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学习资料的答案和解析:
[单选题]62. Usually at weekends the girl will _______.
go to different kinds of training courses
[单选题]2. We were angry __________ him ___________ keeping us waiting.
with; for
解析:2.A【解析】be angry with sb. for sth.因某事而生某人的气。