A：一年一熟、一年两熟、两年三熟
B：三江平原、三江并流、三江源
C：甜菜和春小麦、棉花和冬小麦、甘蔗和水稻
D：嵩山少林寺、北京故宫、苏州园林
世界上人口自然增长率最低的大洲是（ ）
用碳粉还原氧化铜的实验，加热一段时间后，发现装入澄清石灰水的试管出现浑浊，继续加热，但始终没有看到黑色固体变红的现象．实验失败的原因可能是（ ）
阅读理解
Welcome to our school. You can do a lot of things here. Come and join us.
Timetable
Sunday
8:30—11:30
Personal Inventions
You can see many inventions by the students;
you may also bring your own inventions.
Monday
19:00—21:00
Space and Man
Dr. Thomas West
If you want to know more about the universe.
Wednesday
19:30—21:00
Modern Medicine
Mrs. Lucy Green
Would you like to know medical science?
Friday
18:30—21:00
Computer Science
Mr. Harry Morison from Harvard University
Learn to use Windows XP.
若|m﹣2|+|n+3|=0，求m+n的值．
