问题 综合

该图示意图中,阴影表示黑夜,读图回答下列问题。(14分)

(1)这天可能是北半球的     (节气),日期是      

(2)再过      小时A点进入正午。

(3)此时正午太阳高度角在一年中达到最大值的范围是                         

(4)此日C点的正午太阳高度角是          

(5)B点处在         (填“晨线”或“昏线”)上,这一天B点的昼长      小时,日出时刻是      

(6)此时北京时间是____________   (2分)

(7)请描述图中昼夜长短及正午太阳高度角的分布规律(4分)

答案

(1)夏季(节气) 6  22  (2)6小时  (3)北回归线(23°26'N)以北地区     (4)  66°34'

(5)晨线(填“晨线”或“昏线”)    18     3:00      (6)9 (2分)

(7)北半球昼长夜短,纬度越高昼越长,南半球反之;由北回归线向南、北两侧递减。

题目分析:(1)图示晨昏线与极圈相切,北极圈内出现极昼,故判断为北半球的夏至日。(2)图示顺着自转方向,经过AB线即将由夜半球进入昼半球,故判断AB为晨线,故图示A点为晨线与赤道的交点,为6时,正午为12时。(3)图示太阳直射点位于北回归线上,即离直射点越近,正午太阳高度越大,离直射点越远,正午太阳高度越小。故北回归线以北地区正午太阳高度达到一年中最大值。(4)图示C点位于赤道,正午太阳高度=90°-纬度差。(5)图示顺着自转方向,经过AB线即将由夜半球进入昼半球,故判断AB为晨线。图示B点的日出时间为3点,即上午长3:00—12:00,故昼长为18时。(6)图示C点所在的经线为12时,经度为165°E,故计算北京时间120°E,较165°E西面45°,故晚3个小时。(7)全球昼夜长短状况看直射点位置,此时太阳直射点位于北半球,故北半球昼长夜短,越往北昼越长,北极圈及以内出现极昼,南半球反之;赤道上昼夜平分。正午太阳高度分布规律:自直射点向南北两侧递减,此时太阳直射点位于北回归线上。

点评:本题解题关键是掌握二分二至日晨昏线的基本特征,晨线与昏线的判断方法,利用太阳直射点的位置判断昼夜长短和正午太阳高度的分布规律。本题还可结合地球自转角速度和线速度的大小比较;太阳高度的判断等设计试题。

阅读理解

Do you know that it is your own immune system working against the virus that makes you uncomfortable when getting a cold, but not the virus itself? So when you have got a strong immune system and the virus is strong enough too, you will possibly get terrible cold symptoms( 症状) ?

Vitamin C won't stop a cold

It is claimed that Vitamin C helps by increasing white blood cells. However, many tests have shown that it does not prevent colds. At best, it only slightly reduces the rime of symptoms.

Staying indoors won't protect you

One of the most likely sources of cold viruses is your computer mouse or desk. A study of the cold virus in offices found that 47% of desktops, 46% of computer mice and 45% of telephones had cold viruses on them.

Wrapping up warm won't protect you

Colds are more common in autumn and winter. That's because the cool, wet and cold weather drives people indoors, where viruses may more easily jump from one person to another. And the distinct peak in colds(感冒高峰) is in September and early January, which is likely due to the return of students to schools and colleges after the summer and winter vacation.

Old granny's chicken soup is right

Granny's chicken soup is an old cure for colds since a long time ago. Scientists say it is true. Chicken soup does help cure a cold. Many canned soups are just efficient as homemade ones.

小题1: It is ______ that makes you uncomfortable when getting a cold.

A.the virus itself

B.Vitamin C

C.the terrible cold symptom

D.your own immune system小题2: "Staying indoors won't protect you" tells us that ______ indoors.

A.there are many desks

B.there are many telephones

C.there are many cold viruses

D.there are many computer mice小题3:The distinct peak in colds is in September and early January. That's because______.

A.it's in autumn and winter

B.the weather is cool, wet and cold

C.students return to schools and colleges

D.viruses can jump from one person to another more easily小题4:Many canned soups are just efficient as homemade ones. The underlined word "efficient" means _____ in Chinese.

A. 有效的     B. 美味的     c. 值钱的     D. 方便的

判断题