Having mastered the technologies of manned spacecraft, China became the third country in the world manned spaceflight independently.
A. develop
B. to develop
C. developing
D. developed
网友回答
A. develop
(答案→)B. to develop
C. developing
D. developed
解析： 这题考察不定式做定语的用法,当名词被序数词修饰时,应当用不定式做定语,就像这道题: the third country in the world后面接不定式做定语.句意是:掌握了载人飞船的技术后,中国成为世界上第三个独立进行载人飞行的国家.选B.