Question

The country has already sent up three unmanned spacecraft，the most recent ________ at the end of last March.

A．has been launched B．having been launched

C．being launched D．to be launched

 

Answer 1

B

【解析】　独立主格结构作状语，排除谓语动词形式，即A项。“the most recent”与“launch”为逻辑上的被动关系，且“launch”在谓语动词之前发生。