区别：
1、bear
后接动名词、不定式及that从句，指在精神或身体上承受某种痛苦，也可指承担某种责任。
例句
This cloth will not bear washing.
这块布不耐洗.
She couldn't bear to see others suffer.
她不忍看见别人受苦。
2、stand
多用于口语中,常用于否定句中，若用于肯定句,则意为“不屈不挠，经受得起”。 后接动名词、不定式。
例句
I couldn't stand to watch them slaughter the cattle.
我不忍看他们宰牛。
He can't stand traveling in the rush hour.
他受不了在交通最繁忙时出游。
3、tolerate
指忍受某人或某种行为而不反抗，语气最弱（即可用于肯定句也可用于否定句）
例句
It seems that these ants can tolerate temperatures which would kill other species.
看来这些蚂蚁能够忍受可能会置其他物种于死地的温度.
Some old people don't like pop songs because they can't tolerate so much noise. 老年人不喜欢流行歌曲,因为他们不能忍受太大的吵闹声.
