▲It was a small love letter Janet had written. The note could look like a schoolgirl's scrawls about her dream guy. All that was missing was a drawing of a heart with the names John and Janet written in it.

▲句中的 All that was missing 并非主语从句，其实此句真正的主语是 all，that was missing 是修饰 all 的定语从句，意思是“缺少的是……”。all that 在此相当于 what，或相当于the thing that。句末的 with the names John and Janet written in it 是 with 复合结构，作定语，修饰 a drawing of a heart。

▲全句大意：那是珍妮特写的一封小情书，是一名女生潦潦草草写给她的梦中情人的小情书，只差没在上面画一颗写有约翰和珍妮特名字的心形图案。