Which of the following statements are correct regarding antibiotics? i. These are chemicals produced by microbes ii. These are substances produced by our body in response to antigens iii. They block the biochemical pathway of the microbes iv. They play significant role in body's immune system A. ii, and iv. B. i. and iii. C. Ü. and iii. D. i. and iv

The answer is atmosphere. there are four spheres of the earth: 1. geosphere (from greek word 'geo' = ground), 2. hydrosphere (from greek word 'hydro' = water), 3. biosphere (from greek word 'bio' = life), and 4. atmosphere (from greek word 'atmo' = air). a magnetosphere is a region of space around astronomical objects controlled by the magnetic field of that object. through the process of elimination, since lightning is present in the air, it can be found in the atmosphere.