1、及物动词,不用接介词.访问;参观;视察.例如,a friend; a factory 2、不及物动词.后面必须加介词. ①参观访问,做客,下榻.例如,They are visiting in London.他们在伦敦访问. We are visiting at a new hotel.我们在一家新旅馆下榻. ②闲谈.后接with.例如,with a friend on the phone 和朋友在电话中交谈 3、可数名词. ①参观,访问,游览,做客.后接to /from.例如,pay a to sb./pay sb.a 拜访某人 A had a from B.A受到B 的访问. ②视察,出差. ③出诊,就诊. ④闲谈.