非生物因素有什么:get sb. to do sth 是什么意思?

get sb do sth还是get sb to do sth 是get sb. do sth.还是get sb. to do sth. get sb. to do sth 是什么意思? 是offer sb sth还是 offer sb to do sth? get sb to do sth 非谓语词组是什么意思？ 是advise sb. to do sth.吗？ help sb. do sth还是help sb to do sth? help sb. do sth还是help sb to do sth? let sb. do sth.or let sb.to do sth 是hear　sb to do sth 还是hear sb doing sth