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physics )物理 the smallest amount of a substance that is needed for a nuclear chain reaction to take place (核链式反应的)临界质量 the minimum amount of resources, number of customers, etc. needed to start or support a project or an activity, or the minimum size that a project or activity needs to be in order to be successful (启动或支持项目或活动所需的)最小资源量,最低人数;(项目或活动成功所需的)最小规模 The company needs one million customers to reach critical mass and start making a profit. 公司需要 100 万客户才能达到临界规模并开始赢利。 TV via internet could only be developed once a critical mass of households had broadband access. 在足够多的家庭拥有宽带接入时,网络电视才能开发。