问题
选择题
下列除哪一结构外,其余结构在层次上都是一致的? [ ]
A.心脏
B.血液
C.肺
D.果实
答案
答案:D
下列除哪一结构外,其余结构在层次上都是一致的? [ ]
A.心脏
B.血液
C.肺
D.果实
答案:D
阅读下面的短文,完成下面的表格(每空词数不限)。 Ben is twelve years old. He is in Class 5, Grade 7. He likes sports. He plays sports every day. He likes playing basketball, because he thinks it is very interesting. He often plays basketball with his friends after school. He also likes helping other students. He often helps them with homework, clean the classroom and so on. We all like him very much. Linda is fourteen years old. She is in Class 4, Grade 8. She likes music. She always listen to it after school, because she thinks it is relaxing and exciting. She also joins a music club. There she can play the piano and sing.
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Ⅰ.已知溶液导电性与其中离子浓度有定量关系。某兴趣小组设计了以下装置和方法测定空气中SO2含量。你认为可行的操作是________________(填序号)
Ⅱ.Fe2+、SO32-和I-都具有还原性。为了比较其还原性强弱,进行以下探究并回答:
(1)已知:①还原性:SO32-> Fe2+;②FeSO3难溶于水。
(2)在(1)的基础上,完成下列假设。
假设1,还原性:I->SO32-> Fe2+;
假设2,还原性: SO32-> I- >Fe2+;
假设2,还原性: ______________________。
(3)实验探究:现对假设2进行探究。完成实验步骤以及预期的现象和结论。
限选以下试剂:0.1mol/L Na2SO3、0.1mol/L KI、0.1mol/L FeCl3、10%KSCN、新制饱和氯水、淀粉溶液、稀HNO3、1mol/L HCl、1mol/L BaCl2
![]() | 预期的现象及结论 |
步骤1:取1mL0.1mol/L Na2SO3和1mL0.1mol/L KI溶液于试管中,混合后滴入2~3滴新制氯水,振荡。 | |
步骤2:____________________________ _____________________________________ | ____________________________________ _______________________________________ |
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步骤4:____________________________ _____________________________________ | ____________________________________ _______________________________________ |