1. 证明;论证;表明;说明
    To demonstrate a fact means to make it clear to people.

    e.g. The study also demonstrated a direct link between obesity and mortality...
           该研究还表明了肥胖症和死亡率之间存在直接的联系。
    e.g. You have to demonstrate that you are reliable...
           你得证明自己是靠得住的。

2. 显示;表露
    If you demonstrate a particular skill, quality, or feeling, you show by your actions that you have it.

    e.g. Have they, for example, demonstrated a commitment to democracy?...
           例如，他们是否已表现出会致力于民主？
    e.g. The government's going to great lengths to demonstrate its military might.
           该政府正不遗余力地展示其军事力量。

3. 示威;进行示威游行（或集会）
    When people demonstrate, they march or gather somewhere to show their opposition to something or their support for something.

    e.g. 30,000 angry farmers demonstrated against possible cuts in subsidies...
           3万名愤怒的农场主示威抗议可能对农产品补贴进行的削减。
    e.g. In the cities vast crowds have been demonstrating for change...
           在城市里，大批的人群举行示威游行，要求进行变革。

4. 示范;演示
    If you demonstrate something, you show people how it works or how to do it.

    e.g. The BBC has just successfully demonstrated a new digital radio transmission system...
           英国广播公司刚刚成功地演示了一套新的数字无线电传输系统。
    e.g. He flew the prototype to West Raynham to demonstrate it to a group of senior officers...
           他将原型空运到西雷纳姆，向一批高级军官作演示。