prevent sb.from doing sth.区别（防止、阻止某人做某事）prevent sb.from doing sthSTOP sb..from doing sthKEEP sb.from doing sth三者有何区别

prevent sb.from doing sth.区别（防止、阻止某人做某事）prevent sb.from doing sthSTOP sb..from doing sthKEEP sb.from doing sth三者有何区别
prevent sb.from doing sth.区别（防止、阻止某人做某事）
prevent sb.from doing sth
STOP sb..from doing sth
KEEP sb.from doing sth
三者有何区别

prevent sb.from doing sth.区别（防止、阻止某人做某事）prevent sb.from doing sthSTOP sb..from doing sthKEEP sb.from doing sth三者有何区别
前两个短语中 from 可以省略
第三个不能省略 若省略意思就为”让某人一直做某事”

防止某人正想做某事（在做事之前）
阻止某人正在做某事（在做事过程中）
确保某人一直做某事

谁说第三个不能省略from？
照样可以省略
keep sb. (from) doing sth.
让某人一直做某事

赞同一楼第三个不能省略from

都不要省略的好。意思上的差别并不大。