Japanese Junior High about 3 yearsago

英文の誤りを訂正する問題で、1番がわからないです

次の英文の誤りを訂正しなさい。 下線部の語は必ず使う (1) This problem is too difficult to solve it. (2) I think I am impossible to finish this job before d (3) Would you be enough kind to help me with this