这句话中考查的词组是prevent from,而不是from going
prevent sb.(from) doing 防止某人做某事
但是在被动语态中,from不能省略：
He was prevented from going to school because of his illness.
prevent from entering; shut out.
阻止进入；关在外面.
Prevent sb.from doing sth.
阻止某人做某事
prevent from being seen or discovered.
使不被看到或者发现.
prevent from leaving or from being removed.
阻止……离开或移动.