【C12】A．becauseB．whileC．althoughD．so

【C12】A．thenB．whileC．sinceD．where

【C18】A．BecauseB．IfC．AlthoughD．Unless

A．becauseB．althoughC．unlessD．so

【C12】A．becauseB．thatC．whatD．if

【C18】A．becauseB．whileC．whenD．if

【C8】A．thoughB．whileC．so thatD．as