Mark the letter A, B, C, or D to indicate the underlined part that needs correction on each of the following questions.

17. Short-term memory lost can be the result of a serious head injury.

     A. Short-term                     B. lost                                C. can be     D. serious

18. Eating properly helps us to have more energy, improving our health, and stabilize our mood.

     A. Eating                           B. properly                        C. to have     D. improving

19. He was weakening by the disease, and became vulnerable to infection.

     A. was                                B. weakening                    C. and     D. became