你的看法是正确的。这是一个形容词短语在句中作定语，可以改成定语从句的：who was just back from the training class.介词短语不能做同位语。能做同位语的是名词，名词词组，名词性从句。如：Li Hua, monitor of our class, has been invited to visit the USA. 其中monitor of our class 就是名词词组做同位语。Have you heard the news that our football team has lost the match again?其中that our football team has lost the ...
