The earth is a huge sphere. After long-term accurate measurement, scientists know that the polar radius of the earth is 6357 kilometers and the equatorial radius is 6378 kilometers.

(1) After long-term accurate measurement, scientists found that the earth is an irregular sphere with slightly flat poles and slightly bulging equator.

(2) When the earth revolves around the sun, the axis of the earth forms a fixed angle of 66.5 with the orbital plane, and the desktop is parallel to the orbital plane, so the included angle between the axis of the earth and the desktop of the illustrated globe should be 66.5.

(3) Prepare maps, compasses, notebooks, binoculars, cameras, etc. On-the-spot investigation should learn and master general skills such as geographical observation, geographical photography, geographical sketch and geographical specimen making.

So the answer is: (1) irregular sphere with slightly protruding equator and slightly flat poles; (2)66.5; (3) compass; Debate direction; Map; Understand the terrain; Drugs; Treat diseases.