I am pretty sure it is A because you could use a test tube or beaker filled with water and turn it upside down in another container filled with water and then use a hose or something to let the gas into the test tube to displace the water.You can't have use a gas that is soluble in water. am pretty sure it is A because you could use a test tube or beaker filled with water and turn it upside down in another container filled with water and then use a hose or something to let the gas into the test tube to displace the water.
verb (used with object), preserved, preserving. 1. to keep alive or in existence; make lasting: to preserve our liberties as free citizens. 2. to keep safe from harm or injury; protect or spare. 3. to keep up; maintain: to preserve historical monuments.
4. to keep possession of; retain: to preserve one's composure. 5. to prepare (food or any perishable substance) so as to resist decomposition or fermentation. 6. to prepare (fruit, vegetables, etc.) by cooking with sugar, pickling, canning, or the like.