与Microsoft网络用户一样，NetWare网络用户也是按_____位虚拟驱动程

阅读理解。

     Be careful on April 1st! When your classmates say "Your shoe's untied (未系好的)!" it may not be

true. And if you find your alarm clock is set back an hour, this may be a joke (玩笑), too.

     April Fool's Day is a traditional occasion. On that day people play harmless jokes on others and then

shout, "April Fool!" It's a "for-fun-only" day, so people don't buy gifts(礼物)or get the day off work or

school.

     April Fool's Day started in France (法国) in the 16th century. At that time, New Year's Day was

between March 25th and April 1st.

     When New Year's Day changes(改变)to January 1st in the mid-1560s, some people still celebrate

(庆祝) it on April 1st. Others played jokes on them and called them "April Fools".

     Each country celebrates April Fool's Day differently. In France, it is called "April Fish". The French

fool their friends by sticking (粘) paper fish to their friends' backs. When someone finds out this joke, they

shout, "April Fish!" In England, it is bad luck to play an April Fool's joke on someone after midday.

Americans play small tricks on friends and strangers alike.

根据短文内容判断下列句子正（T）误（F）。

( )1. People think Americans started the April Fool's Day.

( )2. New Year's Day was on January 1st five hundred years ago.

( )3. People are late for work on April 1st.

( )4. People don't get the day off work or school.

( )5. A stranger may play jokes on you in America on April Fool's Day.

在我校今年中招体考模拟考试中，某小组6位同学掷实心球的成绩分别为11分，15分，14分，12分，15分，12分，则这6个数据的中位数为______分．

如图所示,甲、乙球的体积相同,此时天平平衡,则ρ_甲:ρ_乙为           。

780B设备中交叉时钟盘1＋1的热备份，工作方式（）。

A.15槽位主用，16槽位备用

B.16槽位备用，15槽位主用

C.没有固定主备关系

D.不确定

在PC-DOS 6.0下，用SYS传送的文件是（）和（）。