李翼 小一下 (2020/09/30) During is preposition. It should be a noun or a sentence after it. I don't know what's the wrong of. ("one of them") .during都已經是介系詞,後面可接名詞或名詞子句,該接one of them也沒錯吧。介系詞也有連結的句子的作用喔:D詳情請查閱維基百科關於介系詞的定義。
During the summer vacation I was_, one of them____. 這樣就有連接詞了貝。