把x=-2代入14x-2a=12,
得-12-2a=12,
解得a=-12.
故答案为-12.
按社会服务计划期限长短分类,可分为长期计划、中期计划和(),它们是一个彼此相辅相成的计划体系。
Teenagers their health because they play computer games too much.
A.have damaged
B.are damaging
C.damaged
D.will damage