What have observed more than 50,000 asteroids

Explanation:

More than 50,000 meteorites have been found on Earth. Of these, 99.8 percent come from asteroids. The remaining small fraction (0.2 percent) of meteorites is split roughly equally between meteorites from Mars and the Moon. The over 60 known Martian meteorites were blasted off Mars by meteoroid impacts.

More than 50,000 meteorites have been found on Earth. Of these, 99.8 percent come from asteroids. The remaining small fraction (0.2 percent) of meteorites is split roughly equally between meteorites from Mars and the Moon. The over 60 known Martian meteorites were blasted off Mars by meteoroid impacts.    

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both anaerobic and aerobic respiration use glucose (or other carbohydrates), proteins and lipids to produce atp and nadh. cell uses those energy molecules, obtained from food and   breaks them down during the chemical reactions of respiration. in anaerobic respiration, nadh is regenerated to nad+ by enzymes lactate dehydrogenase (lactate is produced, e.g. in muscle cells) or by alcohol dehydrogenase where ethanol is produced (alcohol fermentation), while in aerobic respiration, electrons from nadh are deposited in the mitochondria to regenerate nad+ (electron transport chain. anaerobic respiration produces 2 atp per molecule of glucose compared to aerobic respiration where about 38 atp molecules are produced.

the real answer is b. scintillation counter