11.She isn’t clever enough to answer these questions.

=>If she was clever enough, she could anser these questions

      12.Lan works so hard that she is exhausted at the end of the day.

      =>If lan didn't work so hard, she wouldn't be exhausted at the end of the day.

      13.Unless she reveals the truth, everything will be ok.

=> If she don't reveals the truth, everything will be ok

       14.If he doesn’t come home late, we won’t get worried.

=> Unless he come home late, we wont get worried

        15.If the dog weren’t badly treated, they wouldn’t leave the home.

=> the dog were badly treated, so they leaved home

         16.It’s so cold so you can’t go out now.

=> If it wasn't so cold, you could go out now