Seek the Emperor of Geography. It s best to come with a geography teacher

Origin of swamp soil: low-lying terrain, heavy parent material, poor water permeability, humid climate, large surface water, high groundwater level, often in a seasonal or long-term state of waterlogging.

Causes of black soil erosion in Northeast China: The average annual precipitation in Northeast China is not much, but it is concentrated in summer, mostly in the form of heavy rain, due to the destruction of surface vegetation, the runoff is concentrated, the scouring force is strong, and the soil suffers from severe water erosion. The snowmelt runoff that occurs when the snow melts in the spring, washes one layer of the soil when the black soil thaws.

Reasons for the commercial grain base in Northeast China: the land is vast and sparsely populated, the soil is fertile, the grain production conditions are better, there are many farmland with high and stable yield, and there is more surplus grain; The per capita share of grain is large, the commodity rate is high, the potential for increasing production is large, and the investment is small and the results are fast; The terrain is flat, the level of mechanization is high, and the grain production is concentrated and contiguous; With grain production as the center, there is little contradiction between grain production land and land used for the production of cash crops and other crops, and transportation is convenient.

Lack of water resources in North China: North China has developed industry and agriculture, and the demand for water is large; The distribution of water resources in China is uneven, and the precipitation in the north is less. The degree of reuse and recycling of industrial and agricultural water in China is low, the water use technology is relatively backward, the water use efficiency is low, and the awareness of water conservation is weak. Water scarcity is exacerbated by severe water pollution.

Although I am not a geography teacher, I used to be okay in high school, but unfortunately I don't learn this now, I don't remember it clearly, I hope it will help you in your studies!

It is recommended that you buy a copy of the "Middle School Geography ** Detailed Guidance Atlas" Shandong Map Publishing House (you can also buy other atlases of this publishing house, others are cheaper, this is the most expensive but the best), this atlas is very good, including the main knowledge points of high school geography!

Answer: C Method 1: Elimination method: 1. Beijing time is the local time of 120°E.

2. Shanghai is at 121 degrees east longitude, so the noon of Shanghai's shadow measurement should be earlier than 120 degrees east longitude, so it should be less than 12:00 Beijing time, so a and d are excluded;

3. Beijing is west of 120 degrees east longitude, so the noon of Beijing shadow measurement should be later than the noon of 120 degrees east longitude, so Beijing time should be more than 12:00, excluding b.

4. Therefore, the correct answer is c.

Method 2: We know that for every 15 degrees of longitude, there is a difference of one hour in local time. Then each degree difference is 4 minutes. The longitude of Shanghai is greater than Beijing time (120°E), so Shanghai local time should be 4 minutes earlier than Beijing time; On the contrary, Beijing is 16 minutes late, so choose C.

Summary: To make this question, you need to understand the question. You can only understand the questions if you have a basic knowledge of geography. "Pole Measurement" = Local Time; "Beijing Time" = 120 degrees east longitude local time ≠ local time in Beijing.

C, this question examines the difference between local time and district time, when we measure the altitude angle of the sun, it must be 12 o'clock in the local local time, when the local time in Shanghai is 12 o'clock, because the longitude of Shanghai is 121 east longitude, one degree earlier than the district time of Beijing 120 east longitude, so the local time in Shanghai is four minutes earlier than the Beijing time, (one degree is about four minutes, common sense), so in Shanghai you have to measure the height of the sun in four minutes than the time of your watch (Beijing time) to be accurate, the same way to solve the problem of Beijing.

This is closely related to the location of the point where the sun shines. Vernal equinox (, where the sun shines directly at the equator, and the heat decreases sequentially from the equint to the poles; Summer solstice (, the direct point of the sun is located on the Tropic of Cancer north of the equator, when the North Pole is slightly hotter than before, in the polar day, and the South Pole is in the polar night; Autumnal equinox (, where the direct point of the sun moves southward and returns to the equator; Winter solstice (the direct point of the sun is on the Tropic of Capricorn south of the equator, when the South Pole is slightly hotter than before, in the polar day, and the North Pole is in the polar night. The two stages are the coldest because they cannot receive direct sunlight and the solar altitude angle is also the smallest.

Summary: The range of direct solar points moves between the Tropic of Cancer and the Tropic of Capricorn, and the point where the sunlight is perpendicular to the ground (the direct solar point) is the most heated, and the energy received by the two levels decreases in turn, so the natural zone is symmetrically formed from low latitude to high latitude.

The range of direct sunlight points moves between low latitudes and north and south latitudes of 23°26, so the natural zone is symmetrically formed from low latitudes to high latitudes.

7. A (Chile along the Pacific Ocean).

8, B (Yushu is the north latitude, excluding AC, Qinghai is north of 30 degrees north latitude, choose B is appropriate) 9, B10, D (C says the opposite).

11, c (located near the equator, hot to rainforest climate).

12, d (the sea temperature in the same latitude is lower than the land in summer, and the land is lower than the ocean in winter) 13, d (the Mediterranean climate is hot and high in summer, and mild and rainy in winter) 14, b (a low latitude area receives more heat from the sultry sun, the hail has direct rays, the temperature is high, the high latitude area is close to the polar regions, receives less heat, and the temperature is low and sails, so it is wrong; c temperate regions have four distinct seasons throughout the year, and the temperature difference between winter and summer is large, and tropical areas have high temperatures all year round and the temperature difference is small, so it is wrong; d Received by the land and sea divisions, the direction of ocean currents, inland, coastal influences, so irregular, so wrong).

The latitude line indicates the east-west direction and the meridian line indicates the north-south direction.

All meridians intersect at the north and south poles, the length is the circumference of the Earth's semicircle (great circle), and intersects perpendicular to the parallels.

All the parallels are parallel to each other, the length is unequal, and the law of change is from the equator to the poles, and the poles become points.

The first two are d, and the back is not very clear.