e dangerous to表示“去做某事是危险的”be dangerous to do something
for的话就是“对某人来说(去做某事)是危险的”be dangerous for something
for后面加somebody和something意思不太一样
加somebody,用的句式就变成了it's dangerous for somebody to do something对某人来说做某事有危险
加something其实就相当于是to do something,意思一样的,
填fo