白矾的功效不包括（） A.解毒杀虫 B.燥湿止痒 C.截疟 D.止泻止血

LED灯是一种新型的环保节能灯。某款LED灯的额定电压为24V。

额定功率为12W，它与“PZ220V—100W”的白炽灯正常发光时的亮度相当。

(1)该LED灯正常工作时电流是多少安？

(2)每天正常工作5h，使用上述一盏LED灯比一盏白炽灯可节约电能多少千瓦时?

(3)某个家庭原来全部用白炽灯来照明，平均每月照明用电40kw·h，现全部改用LED灯。相同情况下可节能约70％。已知每节约l kw·h电就能减排约1kg的二氧化碳，则改用LED灯后，这个家庭平均每月能减排二氧化碳约多少千克?

To most of us, school means classes, teachers, schedules, grades and tests. But for the children at Sudbury Valley School in Massachusetts, school is very different.

Firstly, there are no lessons. All the children, aged between 4 and 19, do whatever they want. There are no teachers, only “staff members”. The idea behind this is that you do not need to make children learn, because children want to learn anyway. “You do not need to say to a three-year-old, ‘Go explore your environment.’ You can’t stop them!”says Daniel Greenberg, a founder of the school. “But if you make children do what you want all day… they will lose all taste of learning.” At Sudbury Valley School, you will find children talking, reading, painting, cooking, working on computers, studying French, playing the piano, climbing trees, or just running around. Two boys spent three years just fishing!

The other way that Sudbury Valley School is different is that the children can decide the rules. Every week, there is a school meeting where both children and staff have one vote (投票)each—even the four-year-olds. They decide the school rules, how to spend the school money, and even which staff they want and do not want anymore.

When the school first opened in 1968, people said it would never work. But today, the school has 200 students, and 80% of its students go on to college. Even the two boys who went fishing all the time have successful careers today. One of them is a musician and the other is a computer scientist.

小题1:What's special about the school?

A．There is nobody but students there.

B．All the students are of the same age.

C．There are no classes for the students.

D．There are no rules in the school.小题2:What do the students do in the school?

A．They learn everything there from the staff members.

B．They grow up there without learning anything.

C．They spend all the time with their parents.

D．They do whatever they are interested in.小题3:The school seems to believe that children________.

A．learn best when they are doing what they want

B．are too young to learn anything by themselves

C．can look after themselves without any help

D．can't go to college without any hard work小题4:The last paragraph wants to tell us that_         .

A．the writer doesn't like the idea of the school

B．the school is quite successful in its work

C．most of the parents don't believe in the school

D．younger students learn better there than older ones小题5:The underlined word career in the last paragraph most probably means_.

A. family   B. money    C. lifestyle   d. job

—Where have you _______ these days?

—I have_______ to Hong Kong with my friends.

A．been; gone

B．been; been

C．gone; been

D．gone; gone

为了传递信息，我国自周朝起就形成邮驿制度，每到一驿站换人换马接力传递．到宋朝增设“急递铺”，设金牌、银牌、铜牌三种，其中“金牌”1昼夜传递500里（已知1昼夜=24小时，1里=500米），由此可推算出传递“金牌”的平均速度约为多少？

0.9×0.11=( )

A．0.99

B．0.099

C．0.0099

D．0.00099