现在完成时的时态标志.
问题描述：
现在完成时的时态标志.
答
recently, recent years, these days/years, lately, since, for + 时段, in the past few years, ever since, in the last five months, up to now, since then, so far,ever, never, yet, lately, once, twice, three/four times..., already, before, just.