counterbalancing
  對重平衡
  Coun·ter·bal·ance v. t. [imp. & p. p. Counterbalanced p. pr. & vb. n. Counterbalancing.] To oppose with an equal weight or power; to counteract the power or effect of; to countervail; to equiponderate; to balance.
     The remaining air was not able to counterbalance the mercurial cylinder.   --Boyle.
     The study of mind is necessary to counterbalance and correct the influence of the study of nature.   --Sir W. Hamilton.
  counterbalancing
       adj : serving to equilibrate; "he added a counterbalancing weight"