问题补充：
单选题I’msorrytotellyouitisnearlyfivemonths___smithgotinjuredintheleg,butIthinkitwon’tbelong____hecompletelyrecovers.A.after; whenB.before; sinceC.that; whenD.since; before
答案：
D解析考查固定句型。It is +一段时间+since 从句 （一般过去时） It won’t be long before +从句 （一般现在时）故
