back sb / sth ↔ up to provide support or help for someone or something支持（帮助）某人/某事:•The plan's success depends on how vigorously the UN will back it up with action.这个计划成功与否，有赖于联合国是否会积极采取行动加以支持。•The police officers are backed up by extra teams of people at the weekend.到了周末，警察得到了增派人员的支援。⇒BACKUPback sb / sth ↔ up to say or show that what someone is saying is true证实某人的说法，为某人作证; 验证某事:•Jane would back me up if she were here.简要是在这儿，她可以为我作证。•There's no evidence to back up his accusations.没有证据可以证明他的指控。•These theories have not been backed up by research.这些理论尚未通过调查验证。 |