问题
选择题
The __________ to the rocket going into space went wrong, and as a result it exploded and fell into the sea.
A．mark
B．sign
C．symbol
D．signal
答案
D
题目分析：A．mark记号，B．sign迹象，标志，C．symbol象征，D．signal信号，句意：进入太空的火箭信号出了问题，因此它爆炸了掉入海里。根据句意选D。