完整句应该是这样的：The country has already sent up three unmanned spacecraft,the most recent unmanned spacecraft,（one）having been launched at the end of last March.
省略了 unmanned spacecraft,这个我知道，原来应该是由从句省略来的吧？我希望把连词和谓语动词都补全。没有从句，后面的是个非谓语要说有省略的话只有名词被省略，没有连词和谓语的the most recenthaving been launchedat the end of last March. having been，非谓语我是这么想的