It was several years later an American ship paid the first official visit to the island.A.

问题补充：

It was several years later an American ship paid the first official visit to the island.

A. since

B. when

C. that

D. as

答案：

A. since

B. when

(答案→)C. that

D. as

解析：考查强调句。强调句结构为 It is/was + 强调部分 + that从句，本题强调时间状语several years later，选C。