这些动词均有“支持，支援，拥护”之意。
back : 通常指对论点、行动、事业等的强有力支持。
- The management has refused to back our proposals.
管理层拒不支持我们的提议。 - Her parents backed her in her choice of career.
她父母支持她的职业选择。 - Doctors have backed plans to raise the tax on cigarettes.
医生们对提高烟草税计划给予了支持。 - The programme of economic reform is backed (= given financial support) by foreign aid.
经济改革计划得到外资援助。 - a United Nations-backed peace plan
得到联合国支持的和平计划
uphold : 既可指积极努力对陷入困境者的支持，也可指给某人在行动、道义或信仰上的支持。
- As a police officer you are expected to uphold the law whether you agree with it or not.
作为警察，不管你赞成与否都应该维护法律。 - Judge Davis upheld the county court's decision.
戴维斯法官维持了郡法院的判决。
support : 含义广泛，多指在道义上或物质上支持某人，也可指对某项事业的支持。
- My father supported the LabourDemocratic Party all his life.
我父亲毕生都拥护工党／民主党。 - The majority of people in the town strongly support the plans to build a new school.
镇上的大部分人都强烈支持修建新学校的计划。 - I think it's important to support local businesses by buying locally.
我认为购买本地商品来支持本地企业这一点很重要。
sustain : 侧重指连续不断的支持或情感上的支持。
- The cash dividends they get from the cash crop would sustain them during the lean season.
从经济作物中获得的收益能帮助他们度过不景气的时期。 - She was sustained by the strength of her religious faith.
宗教信仰的力量支撑着她。 - The love of my family and friends sustained me through my ordeal.
家人和朋友的爱支撑着我渡过了难关。
advocate : 多指通过写文章或发表演说等来支持或拥护，往往暗示提倡某事或为某事辩护。
- She advocates taking a more long-term view.
她主张把目光放得更长远一些。 - He advocates the return of capital punishment.
他主张恢复死刑。 - Mr Williams is a conservative who advocates fewer government controls on business.
威廉斯先生是个保守派，主张政府应减少对商业的控制。
