15. D.根据前文中“We never
told him he couldn‘t do it… so he didn’t know”，再结合Joey入选校田径队的事实，可推知此处要表达的内容是“他确实参加了”，即Joey是在一种毫不知情的情况下参加了田径队。take的意思有“参加，加入”，故答案选D.
My son Joey was born with club feet. The doctors said that with
treatment he would be able to walk， but would never run very well. The first three years of his life
was ___1___ in hospital. By the time he was eight， you wouldn‘t know he has a problem when you saw him ___2___.
Children in
our neighborhood always ran around ___3___ their play， and Joey would jump and ran and
play， ___4___. We
never told him that he probably wouldn‘t be ___5___ to run like the other children. So he didn’t know.
In ___6___
grade he decided to join the school running team. Every day he trained. He ran
more than any of the others， ___7___ only the top seven runners would be chosen to run for the
___8___. We didn‘t tell him he
probably would never make the team，
so he didn’t know.
He ran four
to five mile every day-even when he had a fever. I was ___9___， so I went to ___10___ him after
school. I found him running ___11___. I asked him how he felt. “Okay，” he said. He has two more miles to go. Yet he looked straight ahead
and kept ___12___.
Two weeks
later， the names of
the team ___13___ were out. Joey was number six on the list. Joey had ___14___
the team. He was in seventh grade - the other six team members were all eighth graders. We never told
him he couldn‘t do it … so he didn’t know. He just ___15___ it.