1．表示过去发生的动作对现在造成的影响或结果。常与recently, before, lately, just, already, yet, so far, up to now, till now, in the past/last years, these days等时间状语连用。
The Browns have visited a lot of places in China so far.
迄今为止， 布朗一家已经游览了中国的许多地方。
He has been there three times in the last few years.
近几年他去过那里三次了。
