1. Thw asteroids are A. Miniature planets B. Satellites of planets C. Pockets of gas in the solar system D. Planets orbiting the stars other than the sun 2. Comets tails are the result of A. Interplanetary material streaming into the comet B. Melting and evaporation of ice from the comets core C. Dust collected by the comet as it moves in its orbit D. Solar wind blowing more gases from the central comet core 3. Why are meteorites and comets important in studying the origin of the solar system? A. They have recently formed themselves. B. They are recently produced fragments of planets. C. They represent the material that formed the planets D. None of the above 4. The orbits of most comets, which we see in the inner solar system A. are nearly circular B. are highly elliptical C. never come closer to the sun D. are only slightly inclined to the earth's orbit 5. Most meteoroids are formed when A. comets melted B. volcanoes erupted C. asteroids exploded or collided D. satellites exploded or collided 6. Meteors are A. falling stars B. signals from the other worlds C. solar wind particles captured by the earth's magnetic field D. luminous trails left by small extraterrestrial particles rapidly
