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.
Preservation as a treatment When the property's distinctive materials, features, and spaces are essentially intact and thus convey the historic significance without extensive repair or replacement; when depiction at a particular period of time is not appropriate; and when a continuing or new use does not require additions or extensive alterations, Preservation may be considered as a treatment.