据统计,1948年当选的“国立中央研究院”第一届81名院士中,有60人选择了留在大陆或在新中国建立之初回到大陆。当时在美国的老舍、曹禺、钱学森等人,经过努力也纷纷回到了祖国。1949年前后,这一批知识分子A. 吹响了“向科学进军”的号角B. 承担着完成民主革命的重任C. 响应了振兴中华的时代感召D. 成为打破中美关系僵局的关键
His entire education ________ no more than one year.
[ ]
A.
added to
B.
added up to
C.
was added up to
D.
was added to