【C2】A．thereforeB．ifC．despiteD．although

【C2】A．thereforeB．thoughC．howeverD．but

【C2】A．RegardlessB．BeneathC．DespiteD．Since

【C2】A．IfB．UntilC．DespiteD．Unless

He failed _____all his efforts.A. in spite ofB. even ifC. although

【C2】A．sinceB．ifC．asD．while

52._________A.or B.although C.and D.despite