2010年考研英语二长难句分析

Application of many celebrities for immigration to Britain seems to have surged_______the concerning policy was released.

在本句中，主谓宾结构非常清晰，application是主语，seems是谓语动词，横线后面也是一个句子，时态为过去式，主句中的时态是现在完成时，根据考点，我们可以推出横线部分天鹅since.