问题 选择题

读“中心天体为太阳的天体运行略图”,回答问题。

小题1:图中共包括的天体系统有  (  )

A.一级

B.二级

C.三级

D.四级小题2:图中最低一级的天体系统的中心天体是  (  )

A.太阳

B.地球

C.月球

D.恒星小题3:此时,北半球正值   (  )

A.春季

B.夏季

C.秋季

D.冬季

答案

小题1:B

小题2:B

小题3:D

题目分析:

小题1:图示包括地月系和太阳系两级天体系统。

小题2:图示最低一级天体系统为地月系,月球绕着地球转,故地球是地月系的中心天体。

小题3:根据连接地心和日心,反映太阳直射点位于南回归线上,故判断为北半球的冬季。

点评:本题解题的关键是掌握天体系统的层次和地球公转轨道图上的二分二至日的判断,本题还可以考查地球在天体系统中的位置。

阅读理解

阅读理解

Do's and Don'ts in Whale(鲸)Watching

     The Department of Fisheries and Oceans has developed guidelines  for  whale  watching  in  Johnstone Strait.where killer whales are found on a daily basis each summer.It is strongly recommended that vessel

operators follow these guidelines for all kinds of whales.

     ●Appmach whales from the side,not from the front or the back.

     ●Approach no closer than 100 metres,then stop the boat but keep the engine on.

     ●Keep  noise  levels  down-no  horns,whistles  or  racing of engines.

     ●Start your boat only after the whales are more than 100 metres from your yessel.

     ● Leave the area slowly , gradually moving faster when you are more than 300 metres from the whales.

     ●Approach and leave slowly , avoiding sudden changes in speed or direction.

     ●Avoid disturbing groups of resting whales.

     ●Keep at low speeds and remain in the same direction if travelling side by side with whales.

     ●When whales are travelling close to shore, avoid crowding them near the shore or coming between

the whales and the shore.

     ●Limit the time spent with any group of whales to less than 30 minutes at a time when within 100 to

200 metres of whales.

    ●If there is more than one vessel at the same observation spot,be sure to avoid any boat position that

would result in surrounding the whales.

    ●Work together by communicating with other vessels , and make sure that all operators are aware of

the whale watching guidelines.

1. For whom is this text written?_________

A. Tour guides.            

B. Whale watchers.

C. Vessel operators.      

D. Govemment officials.

2. When leaving the observation areas, the vessel should________.    

A. move close to the beach

B. increase speed gradually

C. keep its engine running slowly

D. remain at the back of the whales

3. When going side by side with whales, the vessel should_______.

A. keep moving in the same direction

B. surround the whales with other boats

C. travel closer and closer to the shore

D. take a good viewing position

4. What is the shortest safe distance from the whales?_______   

A. 400 metres.                

B. 300 metres.

C. 200 metres.              

D. 100 metres.

单项选择题