75、The windows of our lab 　　　　 (clean) once a week.

74、They are busy 　　　　　 　　(clean) their classroom.

73、Go on 　　　　 　　(work). We still have time.

72、Would you like 　　　　 　(visit) the Summer Palace with me?

71、I’d like you 　　　　　　 　(meet) my parents.

70、Tell him 　　　　　　 (come) here on time.

69、It’s time 　　　　　　 (go) to bed.

68、It makes me 　　　　　　 (feel) thirsty.

67、Stop 　　　　　 (play). It’s time for class.

66、They want to go there on foot. So 　　　 　Lucy . (do)