题干
______ 15 years old, the boy left home for Beijing _______the first time.
A：At, at
B：On, at
C：In, for
D：At, for
答案(点此获取答案解析）
D
______ 15 years old, the boy left home for Beijing _______the first time.
A：At, at
B：On, at
C：In, for
D：At, for
