是to them surprise还是to their surprise

是to them surprise还是to their surprise 是To their surprise还是To their surprises to one's surprise 的surprise固定是不加s?即使是to their surprise? to us surprise还是to our surprise To their surprise为什么不能用过去式? to their surprise.为什么不是surprsed? 使我惊奇是to my surprise还是to me surprise? 是to one's surprised还是to one's surprise? To their surprise, the T-shirts with Olympic Mascots on them be surprise at To one's surprise To my surprise.中surprise的词性? surprise/to our surprise/in surprise/surprising/surprised/be