为探究某些生态因素在生态系统中的作用，有人设计了如下实验，请分析并回答下列问题
实验装置
序号
A
B
C
D
河泥
无
有
水藻
光照
小鱼存活时间
3天
11天
25天
2天
西亚的石油主要输往（ ）
人们常说“油比水轻”实际上是说（ ）
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.
