The Space Age _____in October 1957 when the first artificial

[老外的解释: Commenced means to begin. initiated means to take the lead or lead out in the project. Originates means someone started the idea. Embarked means to begin a journey. Yes, they are all verbs, but each one has a little different meaning. If you use initiated, you would have to say "was initiated by. "If you use originates, that is a present tense form, and you arfe talking about something that happened in ghe past. If you use embark, you are taling ab out one specific trip or journey. If you use commenced, it is he past tense of a started and simply says that the spac age started in such and such a time.