请给我用中文简单讲解一下英文中infinitive / gerund / participles 2...答:(from),keep …from, stop…(from),protect…from, set about, be engaged in, spend…(in), succeed in, be used to, look forward to, object...析:根据warn sb.(not)to do sth.句式,可排除B、D两项;又根据非谓语动词的否定式not总是在首位的规律,又可排除A,而定C。 6.——I usually go ...