八年级暑假学与练科学答案bytt（Eighth grade summer school and practice science answer bytt）.doc

八年级暑假学与练科学答案bytt（Eighth grade summer school and practice science answer bytt） Share has been Shared five times science (a) 1. D 2. A 3. C 4. B 5. The mass of water per cubic metre is 1.0x103 kg. 0.92 8. Oxygen; A wood strip with Mars rekindled; Hydrogen and oxygen are 9. (1) right (2) 120; 1.2 10. (1) 0.1 x 103 (2) 240000 pa (2) B. B. B. Pressure 7. Constant; Increases 8. 5 9. (1) 2.646 * 107 cattle (2) 2.29 x 105 pappa (3) 1. B 2. C 3. C 4. D 5. B 6 7. (1) beaker; Funnel (2) stirring to prevent the filtrate from boiling; Drainage (3) low (4) D 8. (1) S b, S c S a (2) t2; 60 (3) m b m c m a (4) cooling heat-saturated solution; Evaporation dissolves 9. (1) Weighing; Dissolving (2) is small; Big 10. 26.5% (4) (1) the mixture (2) the mixture (2) liquefaction (1) (2) large (3) atmospheric pressure 8. (1) 0.8 x 103 kg/m 3 (2) 5.625 x 105 pa (5) (1) C (2) D (3) B 4. 5. A C 6. (1) is greater than the air pressure is less than below, (2) the plane above the plane get upward pressure difference, so the plane can fly in the sky 7. The boiling point of water decreases with the decrease of the pressure. The device leaks or the water in the bottle is too low 8. (1) the atmospheric pressure decreases with height (3) 0.9 by 105; 0 9. 123 ~ 124 ℃ (6) (1) high pressure; 2. Sunny, the temperature of 18 ~ 27 ℃, south 2 ~ 3 grade; 2 PM; Northeast (2) stratosphere; C 7. Thermometer screen; Dry wet bulb thermometer; Relative humidity; Small; Moisture loss; Hibernation 8. (1) 7; 8; 4. 9 (2) long; Short (3) temperate zone; Subtropical 9. (1) 1, 3 (2) material species; Quality of matter; How much is it heating up (7) (1) (2) (2) tip (3) b (2) photosensitive cell (3) vision on the retina. Exercise 8. (1) photosensitive cells; The optic nerve (2) nervous system; Reflect (3) positive attitude and optimistic attitude 9. (1) the water body of water flea (3) error (4) (8) B 1. B 2. 3. 4 D D 5. A 6. (1) (2) (1) may be slightly battery is power off somewhere (2) may break the 7. (1) C (2) D (3)