不等式-3x＜15的负整数解的和是（ ） A．-10 B．-9 C．-8 D．-7
题型：选择题
问题：
不等式-3x＜15的负整数解的和是（ ）
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题型：选择题
阅读理解。
While scientists are worried that humans are causing higher temperatures on the Earth, a Maryland man, Ace, thinks we can save the world by spraying (喷射) huge amounts of water into the air.
Ace told the McClatchy News Service that at least 1,000 places should be chosen to spray water. The water would be sprayed between 20 and 200 feet into the air. Thousands of tons of seawater would be
sprayed for years at a time.
The 1,000 sites would be picked after more studies. They would be mostly in the Northern
Hemisphere. Ace says he would avoid tropical (热带的) areas of the globe. He says water turns to rain
too quickly in these areas for his plan to work.
The water would be changed into vapor. That process requires heat. The water vapor would rise
above the Earth. The vapor would form clouds. The clouds would help in several ways. They would cool the Earth by reflecting sunlight. They would later turn into rains. The rains would provide another way of
cooling the Earth.
Ace’s plan has gotten some support from a limited scientific study. Kenneth Caldeira is a climate
scientist. He works at the Carnegie Institution’s Department of Global Ecology at Stanford University in
California. Caldeira tested some of Ace’s figures on a computer program. The computer model is used by top scientists to study global climate change. The model showed that the plan might work.
"More tests are planned in 2009. Ideas like Ace’s should be considered carefully and with an open
mind," Caldeira said. “Every brilliant invention in the history of technology looked a little bit mad when first put forward.”
1. What’s the purpose of Ace’s plan?
A. To reduce air pollution.
B. To make summer cooler.
C. To offer dry areas more rain.
D. To solve the problem of global warming.
2. According to Ace’s plan, ________.
A. planes would be used to spray water
B. it would be best to spray water on rainy days
C. seawater would be sprayed high into the sky
D. 1,000 sites in the Southern Hemisphere would be chosen
3. Why wouldn’t Ace spray water in tropical areas?
A. Water is changed i
nto vapor too quickly.
B. Water turns to rain too quickly.
C. It is hard for vapor to form clouds.
D. It is bad for local plants to have too much rain.
4. It seems that Caldeira _________.
A. takes Ace’s plan seriously
B. thinks Ace’s idea too crazy
C. doesn’t believe the computer’s result
D. agrees to carry out Ace’s plan right now
5. According to the passage, Ace can be best described as __________.
A. mad
B. creative
C. mysterious
D. optimistic