He is following a correspondence course in gardening for adults with comparative ease. 他正在上一个相对简单的园艺成人函授课程。
A correspondence course is offered by mail, completed entirely by home study, often with one or two proctored, or supervised examinations. 函授课程是透过函件往返，学生完全是在家以自修方式完成，通常会有一或二次经由学校监督进行的考试。
