Using subjunctive mood:They didn't pack the goods properly, so they got damaged.
【正确答案】正确答案：If they had packed the goods properly，they wouldn’t have got damaged．
【答案解析】解析：译文：他们没有妥善地包装这些物品，所以这些物品被弄坏了。根据题干中的didn’t可知本题可改写为对过去的虚拟，可用if条件句。主句要用情态动词+have done，从属分句用had done。