完全正確答案：
we just couldn't_have imagined you would arrive on time____（本沒想到你能準時到達）,because we had been informed of the terrible jam.為什么不就用：imagine 呢，本沒想到你能準時到達，但你卻準時到了。還是指我沒想到過，過去沒能不就用couldn't do 嗎？couldn't have done 意為不可能做了。。。這是基于對當(dāng)時發(fā)生情況的理解，即本不可能想到，實際上卻想到了?，F(xiàn)在再想起來，實際上我當(dāng)時想得過于復(fù)雜了，實際上重點應(yīng)放在（實際發(fā)生的）估計你居然能準時到達，而原來以為你是不可能準時到的。估計你們老師也沒期望得到那么難的句子。因此，現(xiàn)改為你們老師期待的簡單正確答案。同時，建議你告訴老師because前面應(yīng)去掉逗號。 We had not imagined you would arrive on time____（本沒想到你能準時到達）because we had been informed of the terrible jam.