It was President Xi Jinping visited the navy troops and urged to strengthen naval force

问题补充：

It was President Xi Jinping visited the navy troops and urged to strengthen naval force on April 9, .

A. when

B. which

C. that

D. he

答案：

A. when

B. which

(答案→)C. that

D. he

解析：考查强调句：句意：是习近平主席在四月九号参观了海军，要求他们加强海军的力量。这是强调句。强调句的结构是：It is/was+强调部分+that+其余部分，判断是否是强调句的标准是把强调句结构去掉，这句话仍然成立。所以选C。