求英语非谓语动词题目,具有代表性的,

问题描述:

求英语非谓语动词题目,具有代表性的,

2007年高考英语山东卷单项选择第33题: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 laun...