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问题 选择题

X元素原子的质量数为m，核内中子数为n，则Wg X2+ 离子含有的电子的物质的量约为[ ]

A．mol      

B．mol

C．mol      

D．mol

答案

答案：D

问答题

1、用化学式表示下列微粒．

（1）2个镁离子：______． 

（2）2个氯原子：______．

（3）3个氨气分子：______．

2、请写出实验室里用高锰酸钾制氧气的化学方程式：______．该反应中，锰元素的化合价由反应前的+7价，变为反应后的+6价和______价．
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单项选择题

When I was seven years old my morn was diagnosed(诊断) with cancer. The doctors told us my morn might be saved with surgery(手术). But it could also kill her. She chose to have it.
The day before the surgery I was off school, and my mom planned the best day of my life, everything I loved at seven and everything that would put a smile on my lace. The day began with her waking me up saying, "Kate, I have a surprise for you. Come and see." The surprise was a doll I had wanted for the longest time. Throughout the day, she told my everything that she thought I would need to know to grow up and be a good person; she told me to be the best I could be and that I would always make her proud. We had a picnic in the park, and it was so cold that we moved to the car. The day was filled with laughter. For the first time in a long time I could see she was really happy. I would never forget her smile, or the way her eyes shone as if we were the same age. It was the best day of my life, and I will never forget the conversations we shared.
My mother managed to live through the surgery. Now when I look back, I realize that the best day of my life could be her last and this could be the last day I would remember with her, the last one we shared. I also understand how unselfish a mother is.

What did the writer’s mother do the day before the surgery

A．She stayed at home to have a good rest.

B．She went to the doctor’s for advice.

C．She turned to her family for comfort.

D．She stayed all day with her chil
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