Take three test-tubes. Fill each other with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of Carbon dioxide.

Living organisms use oxygen and release CO2 during respiration.

Test tube A consists of snail which continuously uses the oxygen produced and releases carbon dioxide.

Hence, test tube A will have the highest concentration of carbon dioxide.

blue stars have the highest surface temp

stellar distances are usually expressed in light-years

the measure of a star's brightness is called magnitude

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