VSD的手术禁忌证为（） A.左心室缩小 B.杂音减轻或消失 C.出现紫绀 D.肺淤

A boy called Mario had many friends, and he was proud of it. Whoever he met, he would like to show off(炫耀) how popular he was at school.

One day, his grandpa said to him, “Mario, I know that you don’t have as many friends as you think. Many of them are not true to you.”

Mario thought maybe his grandpa was right. However, he wasn’t sure how he could test whether his schoolmates were real friends or not, so he asked his grandpa. The old man answered, “I have just exactly what you need. It’s in my room. Wait a minute.” The old man left, soon returning as if(好像) carrying something in his hand, but Mario could see nothing there.

“Take it. It’s a very special chair. Because it’s invisible, it will be hard for you to sit on it. However, if you manage to sit on it, you can use the chair’s magic power（力量） to tell who your real friends are.”

Mario took the strange invisible chair to school. At break time he asked everyone to form a circle, and he put himself in the middle, with his chair.

“Nobody move. You’re about to see something amazing，” said Mario. Then he tried sitting on the chair. Having difficulty seeing it, he missed and fell to the ground. Everyone had a pretty good laugh. “Wait, wait,” said Mario, making another try. But again he missed the seat.

Mario didn’t give up. He kept trying to sit on the magic chair. Finally, he did it. This time he felt himself in mid-air.

Then he experienced the magic that his grandpa had been talking about. Looking around, Mario saw George, Lucas and Diana holding him up, so he wouldn’t fall. But some schoolmates whom he had regarded as friends had done nothing but made fun of him. Mario was quite thankful to his grandpa, who helped him test who his true friends were.

小题1:Mario’s grandpa gave him a special chair to _____.

A．sit on in the school

B．be his birthday present

C．test who his true friends are

D．play games with his friends at school小题2:What does the underlined word “invisible” mean in Chinese in the passage?

A．感激的

B．有帮助的

C．神奇的

D．看不见的小题3:Mario succeeded in sitting on his chair finally because_____.

A．his friends taught him

B．he had tried many times

C．his friends held him

D．the chair had magic power小题4:Which would be the best title（标题）for this story?

A．A Magic Chair

B．A Kind Grandpa

C．Mario’s True Friends

D．How to Test Friends

《生活饮用水卫生标准》(GB 5749—2006)中的两虫指标是指( )。

A．菌落总数和隐孢子虫

B．贾第鞭毛虫和军团菌

C．隐陀子虫和贾第鞭毛虫

D．菌落总数和军用菌

（7分）用中和滴定的方法测定NaOH和Na₂CO₃的混合溶液中NaOH含量时，可先在混合液中加入过量的BaCl₂溶液，使Na₂CO₃完全转化为BaCO₃沉淀，然后用酚酞作示剂，用标准盐酸滴定。试回答：

（1）      向混有BaCO₃沉淀的NaOH溶液中滴加盐酸，为什么不会使BaCO₃溶解而影响NaOH含量的测定                             

（2）      达到滴定终点时溶液的颜色如何突变？                      

（3）      滴定时，若滴定管中滴定液一直下降到活塞处才到终点，则能否由此得出准确的测定结果？为什么？                       

（4）      能否改用甲基橙作指示剂？       。若使用甲基橙作指示剂，测定结果如何？

紫苜蓿粗粉及团粒

中长期国债期货采用指数报价法。（）