Finally came the day ——— he had to begin his study for the next term.Atill Bwhen Cwhich Dthat
问题描述：
Finally came the day ——— he had to begin his study for the next term.Atill Bwhen Cwhich Dthat
答
用 WHEN
前面是时间的,后面用when指代,
是人的,用who,或who.