Ask a geography question, everyone help...

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 the spring and autumn equinox, the equinox of day and night around the world, and the sun shines 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.

1. When m coincides with s, it means that the earth has turned to the vernal or autumnal equinox.

So a is correct;

2. The distance from S is the largest, which means that line B is the southern circle, that is, the polar night or polar day appears in the southern circle, that is, on the summer solstice or winter solstice, the height of the earth reaches the Tropic of Cancer or Tropic of Capricorn.

So a is wrong, the direct shot may be East 30, or it may be West 150b error, if it is the summer solstice, the Beijing time is 18 o'clock, if it is the winter solstice, the Beijing time is June 23 at 6 o'clock:

c is also wrong, if it is the summer solstice, the height of the sun at this time in n is just 0, if it is the winter solstice, it is not not 0

d is correct.

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.

Choose C:1The Earth's revolution is slower - the summer half year (the days are longer than the night in the Northern Hemisphere) - plus the AB line is the morning and dusk line, then the AB is the day in the upper right, the night hemisphere in the lower left, and the morning line in the AB.

2.New day range: east of the meridian where the zero point is located to the 180° meridian.

3.From the original diagram (the meridian 20° to the east is 5°, and the west longitude decreases from west to east), it can be seen that the meridian passing through the intersection of the morning line AB and the equator (0° latitude in the figure) is 20°W, so it can be seen that the opposite meridian (which constitutes a meridian coil) is 160°E, and the meridian where the zero point is located is 110°W

4.The uploaded ** is a cross-section, which can be thought of as an equatorial interface or any section parallel to the parallel.

**The upload is very slow, it should be made clear here, let's see it another day**.

Note: This is actually a better way to solve the problem.

1.The division of the new day.

2.The meridian where the change point is located.

4.The morning and dusk line determines whether it is morning or dusk.

5.Morning and dusk look at the autobiography of the earth with the winter half year or the summer half year.

6.The 20° in the other figures should be other small problems: but the conditions on the general questions are useful, and sometimes you can see which conditions are ignored if you don't choose something, and other bad sales subjects are also rented like this.