Upon graduation from university, he was assigned to work as Prof

Upon graduation from university, he was assigned to work as Professor Stevenson's _____. (assist)
【正确答案】：assistant
【题目解析】：译文：他大学一毕业就做了教授史蒂文森的助手。所有格是名词的特性，ProfessorStevenson's是所有格,后面应加assist的名词assistant，意为助理，帮手。答案为assistant。