小儿肥胖的判断方法，常用体重平均值和标准差（S）来估计。测得体重在平均值±2S是（）

设集合U=N，集合M={x|x²-3x≥0}，则∁_UM=______．

受教育既是公民的权利，又是公民的义务。[ ]

On a small farm in Mexico, there are no schools. A bus is the school! The driver of the bus is the teacher! It is a school bus, but it doesn’t take children to school. It just goes round from place to place, and sometimes it comes to this farm. The bus will stay here for three months. The farmers call it a school on wheels (车轮).

Every time the bus comes, the farmers come running to it, shouting and laughing. They warmly welcome the school bus!

When the bus is on the farm, in the morning, the teacher teaches the small children. In the afternoon, the bigger children come to have their lessons because they must work in the morning. At night, the fathers and mothers come to school. They want to learn, too. How the farmers hope that some day they can have a real school on their farm!

小题1:The driver of the bus is ________.

A．the teacher

B．the student

C．the farmer

D．the school小题2: The bus school will ________.

A．take children to school

B．stay there for lunch

C．go round from place to place

D．take the fathers and mothers to school小题3: When the school bus comes, the farmers________.

A．stop working

B．warmly welcome it

C．be happy

D．Both B and C小题4:Which one of the following is true?

A．A school bus is a real school for farmers’ children.

B．The bus school has no teacher at all.

C．The bus school has no students.

D．The children and their parents on the farm all come to the bus school to learn.

粮食仓房的耐火等级是如何规定的？

婴儿1-3岁时的思维方式为（）

A、感知动作思维

B、具体形象思维

C、抽象逻辑思维

D、形象抽象思维