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.
maintain - maintain by writing regular records; keep a diary; maintain a record; keep notes keep. record, enter, put down - make a record of; set down in permanent form. 8. maintain - state or assert; He maintained his innocence defend. vindicate - maintain, uphold, or defend; vindicate the rights of the citizens affirm - say yes to. 9. maintain - support against an opponent; The appellate court upheld the verdict uphold. vindicate, justify - show to be right by providing justification or proof; vindicate a claim