[单项选择]The Space Age ______ in October 1957 when the first artificial satellite was launched by the Soviet Union. A. initiated B. originated C. embarked D. commenced
参考答案:D 答案解析:句意:太空时代开始于1957年10月,那时候第一个人造卫星由苏联发射上空。 initiate是个及物动词,“开始,发起,倡议”,如initiate a constitutional amendment