已知等差数列{an}满足a2+a8=12，则a5=（ ） A．4 B．5 C．6

April Fool’s Day is on April 1st. On this day, strange things may happen. Our friends will play jokes(开玩笑)on us and try to fool us. 

People don’t know the origin (起源) of April Fool’s Day clearly. Some say April Fool’s Day began many years ago in France. Long ago in France, the old New Year’s festival was celebrated from March 25th to April 1st and ended with exchange (交换)of presents. Later the King changed the New Year to January 1st. some people still celebrated the New year in April. They were called April Fish and were given presents as a joke.

But in many countries, April Fool’s Day is not celebrated on April 1st but on other days. In Mexico( 墨西哥), April Fool’s Day is on the 28th of December. In ancient Rome (古罗马), the day was on the 25th of March. In India, the day is on the 31st of March. In America, the day is mostly decided by young people and jokes who want to make fun of other people. But it is important to remember that your friends and you will be both happy. One must remember the difference between a good joke and a bad one.

小题1:When is April Fool’s Day in France now?

A．April 1st

B．March 25th

C．December 28th

D．March 31st小题2:What do people do on April Fool’s Day?

A．Give presents to friends.

B．Play jokes on friends.

C．exchange presents.

D．Do nothing special.小题3:Is April Fool’s Day in Mexico on the twenty – fifth day in March?

A．Yes, it isn’t.

B．No, it isn’t.

C．Yes, it is.

D．Sorry, we don’t know.小题4:People know the origin of April Fool’s Day clearly, don’t they?

A．Yes, they do.

B．No, they do.

C．Yes, they don’t.

D．No, they don’t.小题5: Which sentence is right?

A April Fool’s Day is on the same day all over the world.

B In America , young people can’t decide the day when they want to play a joke.

C New Year’s Day is from March 25th to April 1st now.

D Please remember to play a good joke on April Fool’s Day.

刚能引起人耳痛觉的声音强度称为（）

A.痛阈

B.声强级

C.响度

D.感觉阈

E.听阈

下列哪种检查不适合于肾损伤

A．大剂量静脉肾盂造影

B．逆行尿路造影

C．B超检查

D．CT检查

E．肾动脉造影

请在“答题”菜单下选择“电子表格”命令，然后按照题目要求打开相应的命令，完成下面的内容，具体要求如下：

选取“某企业人员开支情况表”的“人员类型”列和“工资额度”列单元格的内容(不包含“总计”行)建立“簇状条形图”，轴上的项为人员类型(系列产生在“列”)，图表标题为“人员开支情况图”，插入到表的A9:D22单元格区域内。

人员携带较长金属物件时要严防物件触及架线。