oblig·a·to·ri·ly /əˌblɪgəˈtorəlɪ, ɑ, ˈtɔr , ˌɑblɪgə-/ 副詞
  Ob·li·ga·to·ri·ly adv. In an obligatory manner; by reason of obligation.
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  obligatorily
       adv 1: in an obligatory manner; "this rule applies obligatorily"
              [ant: optionally]
       2: in a manner that cannot be evaded; "the ministry considers
          that contributions to such a fund should be met from
          voluntary donations rather than from rates compulsorily
          levied." [syn: compulsorily, mandatorily]