双基限时练(十一) unit 4 part ⅱ 基 础 夯 实 ⅰ.单项填空 1．— how long do you think it is ________ he arrived here? — no more than half a year, i believe. a．when b. that c. before d. since 答案与解析 d since引导的状语从句中arrived为终止性动词的过去式， since表示“自从……以来”。 2．it was not ________ she took off her dark glasses ________ i
