1、exist
存在;实际上有
He thought that if he couldn't see something, it didn't exist.
他认为自己看不见的东西就不存在。
Research opportunities exist in a wide range of pure and applied areas of entomology.
纯理论昆虫学和应用昆虫学的众多领域都存在着研究机会。
（尤指在逆境中）生存，生活
I exist from one visit to the next.
我的生活就是一个接一个的访问。
I was barely existing.
我勉强维持生计。
2、believe
相信；认为
Experts believe that the coming drought will be extensive.
专家们认为即将发生的旱灾将侵袭大片地区。
I believe you have something of mine.
我想你拿了我什么东西。
相信（某人或某人的话）
He did not sound as if he believed her.
他听起来似乎并不相信她。
Never believe anything a married man says about his wife.
永远不要相信一个已婚男人说的任何有关他妻子的话。
认为…是应该的（或正确的）
He believed in marital fidelity.
他认为婚内应该忠诚。
decent candidates who believed in democracy.
信奉民主政治的正派候选人