【C7】A．unlessB．otherwiseC．ifD．because

【B15】______A．thatB．whenC．ifD．because

【C4】A．howeverB．whileC．ifD．because

【C7】A．althoughB．becauseC．only ifD．when

【C15】A．UnlessB．IfC．BecauseD．Since

【C7】A．such thatB．just likeC．as ifD．much as

【C7】A．according toB．related toC．based onD．because of