【C15】A．revert toB．hand onC．get inD．act on

These products are superior（) those we bought last year.A toB ofC inD on

Fifty million Americans are addicted（) nicotine.A toB atC inD on

【C11】A．up toB．toC．inD．on

【C2】A．take toB．take onC．take inD．take up

【C15】A．ThereforeB．AlthoughC．ConsequentlyD．On the other hand

They succeeded _____ overcoming the difficulties they encountered .A.toB.onC.inD.of