look at sb do 还是look at sb doing?

look at sb do 还是look at sb doing? 紧急】see sb do/doing sth,watch sb do/doing sth,look at sb do/d 用run around with sb look around 造句 用look at sb doing sth 造句 造句：hear sb do sth .look at sb do sth.make sb do sth .notice 请问什么时候用 see sb doing sth 什么时候用 look at sb doing sth 轻视某人是look down sb还是look down at sb? 用look at sb/sth造句 用look at sb sadly造句 look in sb和look on sb和look at sb 有什么区别?我怎么只知道有at look at doing sth see/hear/look sb.do/doing sth.的区别 look down at sb 和look down on sb的区别?怎么用?