题目内容
【题目】人类利用卫星技术精确测量出地球赤道的周长，其长度大约是多少千米？（ ）
A. 6371 B. 4万
C. 5.1亿 D. 8万
【答案】B
【解析】试题分析：经过测量，地球的极半径为6357千米，赤道半径为6378千米，地球的平均半径为6371千米，地球表面积为5.1亿平方千米，最大周长约4万千米．
解：赤道的周长大约是4万千米，赤道是地球上最长的纬线．
故选：B．
每日10分钟口算心算速算天天练系列答案
【题目】
| This boy demonstrated his invention a pen with a reading glass，in Harbin on January 20，2009.Over 16 small inventions have been made since a training course was opened at the Science Palace in Harbin in November，2008. |
| This boy's invention，which can cut an apple into pieces，was demonstrated in Harbin on January 20，2009. |
| This boy invented a musical alarm clock which he demonstrated in Harbin on January 20，2009. |
| This small car was invented in March，2010 by a college student.It has 250 cm long and 100 cm wide.The car weighs less than 50 kg.It only has one seat. |
【1】When was the training course opened at the Science Palace in Harbin?
A. In January，2009. B. In November，2008.
C. In May，2009. D. In March，2010.
【2】Which invention is the latest?
A. The small car with one seat.
B. The musical alarm clock.
C. The pen with a reading glass.
D. The machine which can cut apples into pieces.
【3】The third boy invented something that can help people ________.
A. cut an apple into pieces
B. wake up every morning
C. take the bus conveniently
D. see words clearly
【4】The underlined word “demonstrated” in the passage means “________”．
A. showed B. drew C. imagined D. divided
【5】The passage mainly talks about ________.
A. several new inventions
B. students' school life
C. the training course in Harbin
D. the Science Palace in Harbin
