threshold

n.门槛；门口

threaten with, threatening, three, three-, three-decker, three-legged, three-legged race, three-line whip, three-piece, three-ply, three-point turn, three-quarter, threefold, threepence, threepenny, threepenny bit, threescore, threesome, thresh, thresher, threw, thrift, thriftily, thriftiness, thrifty, thrill, thriller, thrilling, thrive, thriving, throat, throatily, throatiness, throaty, throb, throes, thrombosis, throne, throng, throttle,