“在…上”用英语怎么说

这个男孩在上小学的时候就初次显示出成为运动员的潜力。The boy first showed promise as an athlete in grade school.我在上大学时懒得要命。I never did a stroke of work at college.我在上大学前空闲的一年里周游了世界。I went around the world in my gap year....