When he looked up, he suddenly found himself          by a group of teenagers,

A．to be surrounded;

B．surrounded;

C．be surrounded;

D．having been surrounded;

1945年，在______上，决定成立“联合国”．

A．德黑兰会议

B．开罗会议

C．雅尔塔会议

D．波茨坦会议