ExercisesContentsDownloadsMIDDLE · UNIT 8: PRESENT CONTINUOUSQuestion 1 / 15请完成全部题目,最后查看答案与解析GRAMMAR · A1 · TYPE YOUR ANSWERExercise 1 · FormComplete with am, is or are + verb-ing.I _____ for the bus. (wait)输入单词、短语或完整答案;多空答案用 / 分隔保存并进入下一题 →