It′s hard to study and work / at a full time job能说的详细点吗It′s hard to study and work + at a full time job and 并列 study 和work....这句话是it 来指代 to study and work （因为主语太长了，按照外国人的习惯， 用it 来指代它）如果按照中文的习惯 ， 就应该是 To study and work is hard at a full time job. 如果你这样说， 老外会觉得很奇怪。