A simple geography problem, everyone come and help

A and D are impossible, and as for B and C, C is also not correct in winter, so choose B

1.Aswan on the Tropic of Cancer: June 22 is the summer solstice, the sun is shining, and the area north of the Tropic of Cancer has the longest daytime button.

2.Measure the solar altitude angle: The length ratio of the bamboo pole to the shadow is the tangent of the solar altitude angle.

3.Measure the distance between Alexandria and Aswan: camel travel speed * time.

4.From the distance between the Sun and the Earth to the radius of the Earth, as well as the angles and distances measured above, the angles of the two places can be calculated, and finally the arc length of each degree can be multiplied by 360° even the circumference.

1: On the Tropic of Cancer. Reason: The sun can reach the bottom of the well at noon on June 22, and the sun will shine directly on the Tropic of Cancer on June 22.

2: Measure the height of the noon sun in Alexandria on that day. Algorithm: The ratio of the length of the bamboo pole to the length of the shadow is the tangent of the pure angle of the sun height.

3: Measure the distance between Aswan and Alexandria. Algorithm: km).

4: Bright crack (1) The latitude difference between the two places can be obtained from 1 and 2. Algorithm: Aswan's noon solar deficit altitude angle (90 degrees) - Alexandria noon solar altitude angle (calculated from 2).

2) The length of each longitude can be obtained from (1) and 3. Algorithm: distance between two places (840 km) Latitude difference between two places (obtained from step (1)).

3) Perimeter = the length of each longitude pair (obtained in step (2)) * 360

1. a。When m coincides with s, it means that the global day and night are equinoxes, and the time is judged to be the spring or autumn equinox.

At this time, the direct point of the sun is located at the equator, and the height of the sun at noon decreases from the equator to the north and south, so a is correct. b describes the months of June and July; c refers to the winter in our country, around the winter solstice; d is from July to September, and the summer is the main flood season of the Tarim River. So choose A.

2. d。It can be seen from the maximum MS distance when MN coincides, and the arc B is the Antarctic Circle, so at this time, the Antarctic Circle is either polar day or polar night, (this point cannot be further judged due to the constraint of the question stem condition, and no judgment is required) Therefore, the length of the day in n is 0 or 24 hours, and D is correct.

A and B both describe the day of the summer solstice and omit the day of the winter solstice; Since the sun is still on the morning and dusk line at noon on the day n, and the solar height at all points on the morning and dusk line is 0, the c term is wrong. Pick D.

In fact, if you can't understand the diagram for this question, you can complete the diagram first. As you can see, this is a projection of the South Pole as the center.

1.When the M point coincides with the S point, it can be judged that the morning and dusk line just passes the South Pole, which can be judged as the spring equinox or autumn equinox. then only option A is eligible.

The meridian of the point is 30° east longitude, and when m coincides with n and the distance from point s is the largest, it can be judged that there are two cases when m and point s are the largest, one is June 22 (the summer solstice in the Northern Hemisphere) and the other is December 22 (the winter solstice in the Northern Hemisphere). It can be judged that the day length of n is 0 (June 22), the day length is 24 (December 22), and the noon sun height must be considered only on June 22, and the B item is wrong.

When the point coincides with the point S, it is exactly the spring and autumn equinox, the global day and night equinox, and the sun is directly on the equator, so a is correct.

b. The rainy season in the Yangtze River basin is June and July.

c At that time, there was no polar day in Antarctica, which was not suitable for investigation.

The Tarim River enters the flood season in the summer.

2。The arc A is the morning and dusk line, if M and N coincide, and the distance between M and S is the largest, then the direct sunlight must be on the meridian where Mn is located, that is, 30 °E, if it is 150 °W, then it is the Antarctic Pole Day, the sun should be directly on the Tropic of Capricorn, Mn can not coincide, so A is wrong.

b At this time, 30°E is 12 o'clock at noon, and the difference between Beijing time is 120-30=90°, that is, 6 hours, and Beijing is east of 30°E, so Beijing time is 12+6=18 o'clock b is wrong.

c, at this point it is clear that the solar altitude is greater than 0 degrees correctly.

d, n at this time there is no polar day or polar night.

Question 1 chooses a because m s coincides with equinoxes and the sun hits the equator directly, so the height of the sun decreases from the equator to north and south. It should be a direct shot at 30 b east longitude, it should be 18 o'clock on June 21, d should be 0 hours, and it cannot be 24 hours.

The answer is wrong, the Southeast.

It's okay to judge the South.

There is a theorem: the east and west meridians are judged by position: the sum of two degrees of longitude is less than 180 degrees, the east longitude is in the east, and the west longitude is in the west; The sum of two degrees of longitude is greater than 180 degrees, east longitude is in the west and west longitude is in the east. (Asking for the position of one is east longitude and one is west longitude).

If the two are both east or west longitude, they are judged according to the direction of longitude.

There is also a drawing to find, the shortest distance between the two meridians is 180 degrees, the difference is only 45 degrees, and a drawing can also be obtained.

The answer is wrong, the correct answer should be southeast.

Just look at the latitude and longitude of the two places, look at the latitude: C is south of D; Look at longitude: if the sum of longitude is less than 180°, then east longitude is in the east and west longitude is in the west, if the sum of longitudes is greater than 180°, then west longitude is in the east and east longitude is in the west, so c is east of d.

Conclusion: Point C is southeast of point D.

The longitude of Cd adds up to more than 180 degrees, C is the west longitude, D is the east longitude, so in the west, C is 40°N, D is 50°N, so C is in the south of D, so southwest.

Southeast, because the CD sum is greater than 180 degrees, then the west longitude is easterly, and the east longitude is westerly, and then because the cd is in the northern hemisphere, because the latitude of c is smaller than d, so it is in the south, and the combined answer is southeast.

Isn't this question simple, cd longitude adds up to more than 180 degrees, c is west longitude, d is east longitude, so in the west, c is 40 °N, D is 50 ° N, so C is in d south, so southwest, how do you learn LZ geography? Hehe.

The answer is wrong, to see the position of the two points in the same plane (i.e., on a globe can be seen at the same time), in fact, it is very simple to think of the following globe.

The shaded part is evenly distributed from north to south, indicating that the sun is shining on the equator; As can be seen from the figure, each grid is 30 degrees of longitude, planed from the black and white dividing line, black and white each occupy 6 squares, choose white, the middle grid point is the direct longitude, that is, the number of three squares from the black and white dividing point to white, the third grid is the prime meridian to the right, the prime meridian is 0°, and the right grid is 30° east

It's very simple, the earth rotates from west to east, so the inner edge of the shadow is 6 a.m., the sun is in the east, and 6 o'clock is pushed back to 12 o'clock which is 30 degrees east longitude.

The north and south equinoxes of the night indicate that the sun shines directly on the equator, and w60 to e120 is exactly 180 degrees when black and white are handed over, corresponding to the sun sub e30

The prime meridian is about 0 and three parts each.