應(yīng)該不能用when的.應(yīng)該說：It's years since I enjoyed myself so much.我已經(jīng)有多年沒這么高興過了.要用when,那it's后的名詞就應(yīng)該是某個(gè)時(shí)間點(diǎn).如：It was the year of 1949 when the People's Republic of China ...我在一本練習(xí)冊(cè)上看到的，一般不會(huì)出錯(cuò)的啊什么練習(xí)冊(cè)？看錯(cuò)答案的吧？It was the year of 1949 when the People's Republic of China was founded.這是定語從句的。老師說這里when引導(dǎo)了一個(gè)表示時(shí)間的定語，怎么理解？那這里的years就應(yīng)該加冠詞，特指。It was the years when I enjoyed myself so much.那是那些年，我非?？鞓?。（其實(shí)這里的years盡管有幾年，但還是時(shí)間點(diǎn)的）但years是時(shí)間段。（因?yàn)椴恢朗嵌嗌倌辏﹚hen引導(dǎo)的是定語從句，when在從句中指時(shí)間。