on the internship
on the probationary period
报道中的“probationary period”就是求职者必须经历的"试用期",也可写做“probation period”、“probationary employment period”或“trial period”.
“Probation”在此指“（以观后效的）查看”,也可和介词“on”连用,表示“在试用期”,如：We'll have to take you on one month's probation first（我们得先试用你一个月）；He is a mechanic on probation（他是个见习机械工）.
此外,probation常用来指“缓刑”,如：three years' probation under suspended sentence of one year's imprisonment（一年有期徒刑缓刑三年）.