问题 选择题

如图分别表示甲、乙、丙三人由A地到B地的路线.

甲的路线为:A→C→B

乙的路线为:A→D→E→F→B,其中E为AB的中点

丙的路线为:A→I→J→K→B,其中J在AB上,且AJ>JB

若符号「→」表示「直线前进」,判断三人行进路线长度的大小关系为(  )

A.甲=乙=丙

B.甲<乙<丙

C.乙<丙<甲

D.丙<乙<甲

答案

根据以上分析:所以图2可得AE=BE,AD=EF,DE=BE,

∵AE=BE=

1
2
AB∴AD=EF=
1
2
AC,DE=BE=
1
2
BC.

∴甲=乙

图3与图1中,三个三角形相似,所以

JK
AI
=
JB
AJ
=
BK
IJ
=
JB
AJ
AI
AC
=
AJ
AB
=
IJ
BC

∵AJ+BJ=AB,

∴AI+JK=AC,IJ+BK=BC

∴甲=丙.∴甲=乙=丙.

故选A.

填空题
阅读理解

阅读理解。

     Since weeks ago,China has been involved a worldwide A/H 1 N 1 flu that has already killed more than 80

people in the middle of May,2009,in Mexico and has turned into a global pandemic.

     The central government has asked people entering China from the virus-hit countries to report flu-like

symptoms (症状)to the authorities. In an emergency notice issued on Saturday night,the country's top quality

watchdog ordered the Customs to check passengers' temperature,too.

     A Beijing airport official Li said Customs officers are on a high alert (警戒) level.

     "Three temperature detectors are now in operation. We' re ready with protection garments and equipment,

too. Passengers flying in from Mexico and other A/H1N1 flu-hit countries are being monitored closely,"he said.

     The Ministry of Health,however,said yesterday there was no evidence to suggest that a person would

contract the disease by eating pork.

     Hong Kong,too,has raised its alert level against the flu to"serious". Secretary for Food&Health,Mr. York

Chow urged people to avoid visiting places from where A/H1N1 flu cases have been reported,and said the virus would be added to Hong Kong's list of the diseases which have been noticed.

     The terrible A/H1 N1 flu has been contracted by about 4000 people in Mexico,and most of the killed were

aged between 25 and 45.

     The virus has also infected about 5000 people in the US. The US Center for Disease Control said this kind

of virus is spreading from human to human,raising fears of a global pandemic. 

1. What is the passage mainly about?

A. A/H1N1 flu killed more than 80 people.

B. A/H1N1 flu is spreading from human to human.

C. China has begun to take steps to prevent A/H1N1 flu.

D. All the people are strongly affected by A/H1 N1 flu.

2. The underlined word "pandemic" in the first paragraph probably means _____.

A. death

B. panic

C. enemy

D. disease

3. Why does the flu cause global fears?

A. Because most people in the world eat pork.

B. Because it's spreading from human to human.

C. Because we still don't know the cause of it.

D. Because it has infected about 5,000 people.

4. According to the passage,which of the following is TRUE?

A. People would contract the A/H1N1 flu if they often eat pork.

B. The virus of the A/H1N1 flu has infected people all over the world.

C. People from AH1N1 flu-hit countries are all forbidden to enter China.

D. People should avoid visiting places where A/H1N1 flu cases have been reported.

5. We can infer from the passage that _____.

A. Students in the middle school are most likely infected by A/H1N1 flu.

B. A person would be infected by the virus by eating pork.

C. Passengers from the United States are being monitored closely.

D. Mr. York Chow said that the virus had been added to Hong Kong's list of the diseases