Klinefelter syndrome (47, XXY) usually comes to attention because of gynecomastia and small testes. These males usually are clinically normal at birth. Treatment involves replacement therapy with a long acting testosterone beginning at age 11 to 12 years.
These are my suggestions for the final part of your homework: 6 - A; 7 - B; 8 - D; 9 - C; 10 - C.
The exercise follows the Sequence of Tenses rules.
For 2 the answer is C because you have two simultaneous actions which need same tense like, the Present.