When every one ___ models themselves on a droplet that is ready to sacrifice itself for the greater good, we need not worry that our work is not important enough to make a lasting change.A. does their workB. did their workC. done their workD. doing their work

本题考查动词时态和主谓一致的用法。关键点在于：

1. 从句时态与主句一致：主句用一般现在时，从句描述普遍现象，也需用一般现在时；
2. 主谓一致：主语every one为单数概念，谓语动词需用第三人称单数形式；
3. 固定短语搭配：model oneself on表示“以...为榜样”，注意代词themselves的使用。

选项分析

• A. does their work
  正确。does为第三人称单数形式，与主语every one一致；their与every one的单数概念不冲突（英语中常用复数代词指代单数概念）。

• B. did their work
  错误。did为过去时，与主句we need not worry的现在时态不一致。

• C. done their work
  错误。done为过去分词，不能单独作谓语。

• D. doing their work
  错误。doing为动名词，不能直接作谓语动词。

关键结论

一般现在时 + 第三人称单数谓语 + 固定短语搭配是本题的解题核心。