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问题 单项选择题

工伤职工()不停止享受工伤保险待遇。

A、拒绝治疗的

B、丧失享受待遇条件的

C、重新就业的

D、拒不接受劳动能力鉴定的

答案

参考答案：C

阅读理解
阅读理解。
Time
Class
8:00～8:50
History
9:00～9:50
Math
9:50～10:05
Morning break (课间休息)
10:10～11:00
English
11:10～12:00
PE
12:00～12:50
Lunch
1:00～1:50
Drawing
2:00～2:50
Biology
     Hi, my name is Kim. This is my class schedule. I have to wake up early every day at about 6:30. First,
I have breakfast. Then.I ride my bike to school. It takes me 20 minutes to get there.
     I have four classes in the morning. I like history best. Mr. Rudolph is really cool. He knows everything
about history, and he tells us lots of funny stories. We also get a 15 minutes' break in the morning. I usually
talk to Ben or Franklin at that time. We also eat lunch together, near the football field at school. 
    The afternoon is easier, since I only have two classes. Biology is my favorite. We got to do fun experiments.
I want to be a doctor ode day. Drawing is also fun. Our teacher, Mrs. Lester is nice. She encourages us even
if our drawings are had. After class, I ride my bike home. I spend about an hour doing homework. Then, I go
out with my friends for some time.
1. How many classes does Kim have a day?
[ ]
A.Four.
B.Five.
C.Six.
D.Seven.
2. How does he go to school?
[ ]
A.By bike.
B.By bus.
C.By car.
D.On foot.
3. Where does Kim have lunch?
[ ]
A.At home.
B.At school.
C.In the restaurant.
D.In the football field.
4. What does Kim want to be when he grows up?
[ ]
A.A doctor.
B.A teacher.
C.An actor.
D.An artist.
5. How long does it take Kim to do homework every day?
[ ]
A.About half an hour.
B.About one hour.
C.About one and a half hours.
D.About tow hours.
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问答题

硫代硫酸钠（Na2S2O3）可看成是一个S原子取代了Na2SO4中的一个O原子而形成．某校化学研究性学习小组运用类比学习的思想，通过实验探究Na2S2O3的化学性质．

【提出问题】Na2S2O3是否与Na2SO4相似从而具备下列性质呢？

猜想①：______；

猜想②：溶液呈中性，且不与酸反应；

猜想③：无还原性，不能被氧化剂氧化．

【实验探究】基于上述猜想②、③，设计实验方案．

实验操作实验现象或预期实验现象现象解释（用离子方程式表示）
A．______溶液pH=8
猜想②向pH=2的硫酸中滴加Na2S2O3溶液B．______S2O32-+2H+═S↓+S02↑+H2O
猜想③向新制氯水（pH＜2）中滴加少量Na2S2O3溶液氯水颜色变浅C．______
【实验结论】Na2S2O3能与酸反应，具有还原性，与Na2SO4的化学性质不相似．

【问题讨论】

（1）甲同学向“探究‘猜想③’”反应后的溶液中滴加硝酸银溶液，观察到有白色沉淀产生，并据此认为氯水可将Na2S2O3氧化．你认为该方案是否正确并说明理由______．

（2）请重新设计一个实验方案，证明Na2S2O3被氯水氧化．该实验方案是______．
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