1.leave of absence from a course of study, granted for the purposes of carrying out additional research
1.He delved further into lung development, spending his study leave in 1971 in a lab in the old Radcliffe observatory in Oxford.
他开始对肺部进行进一步研究，1971年他利用进修假前往牛津瑞德克里夫老天文台的实验室。