酸中毒时，血钾浓度变化趋向是A．升高B．下降C．无变化D．先高后低E．先低后高

选出错误部分并在题后的横线上写出正确的答案。

(     )1. What's time  is  it? _____                                    

                A      B    C

(     )2. It's  half  to  six. _____                                        

             A    B   C

(     )3.  It's time for go to school. _____                                   

               A         B              C

(     )4. I get up in a quarter to seven. _____                                 

                 A     B             C

(     )5. Mike and I am on duty today. _____           

                  A          B     C

看图回答问题。

1. —Where is the trash bin? 

    —                               

2. —Where is the chair? 

    —                               

3. —Where is the picture? 

    —                               

4. —Where is the ruler? 

    —                               

5. —Where are the books？

    —                               

如下表提纯下列物质（括号内为杂质），所用的除杂试剂和分离方法都正确的是(   )