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问题 问答题

某房地产开发公司房屋的实际销售收入如下表，以三年为移动期，试用移动平均法预测其2005年的房屋销售收入为多少万元

年份 2000 2001 2002 2003 2004
销售收入(万元) 1800 2100 2300 2100 2300

答案

参考答案：2005年的房屋销售收入为2366.65万元。

解析：按题意可列表如下：

年份

实际销售收入(万元)

每3年的移动平均数(万元)

移动平均数的逐年增加额(万元)

2000

1800

-

-

2001

2100

2066.67

-

2002

2300

2166.67

100

2003

2100

2233.33

66.66

2004

2300

-

-


预测2005年的销售收入：2233.33+66.66×2=2366.65(万元)

单项选择题

钻井法凿井过程中一般不需要的工序是（）。

A.泥浆护壁 

B.壁后充填 

C.振动 

D.沉井
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单项选择题

Since life began eons ago, thousands of creatures have come and gone. Some, such as the dinosaurs, became extinct due to naturally changing ecologic conditions. More recent threats to life forms are humans and their activities. Man has drained marshes, burned prairies, dammed and diverted rivers. Some of the more recent casualties of man’’s expansion have been the dodo, great auk, passenger pigeon, Irish elk, and Steller’’s sea cow. Sadly, we can no longer attribute the increasing decline in our wild animals and plant species to "natural" processes. Many species are dying out because of exploitation, habitat alteration or destruction, pollution, or the introduction of new species of plants and animals to an area. As mandated by Congress, protecting endangered species, and restoring them to the point where their existence is no longer jeopardized, is the primary objective of the U.S. Fish and Wildlife Service’’s Endangered Species Program.

According to this passage,________

A．man is the cause of some animal extinction

B．animals often bring about their own extinction

C．Congress can absolutely end extinction of animals

D．a law is more important than human responsibility
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