Give the correct form of the verbs in brackets :
21. The police didn’t permit ( camp ) in this wood for security reasons .
22. We don’t allow people ( smoke ) in the lecture room.
23. The teacher advised ( review) the grammatical structures carefully .
24. He’ s used to ( go ) on foot to work .
25. We get used to ( work ) on Sundays .
26. She is looking forward to ( see ) her friends .
27. Sometimes students avoid ( look ) at the teacher if they don’t want (answer ) a question.
28. You should try ( wear ) any shirts you want to buy.
29. The teacher recommends us ( prepare) the lessons well before ( come ) to class.
30. There are people can’t help ( laugh )when they see someone ( slip ) on a banana skin
31. He went to bed without ( lock ) the doors .
32. They don’t have enough patience ( wait ) for him .
33. Gravity makes water ( run ) downhill .
34. This man let me ( use ) his phone yesterday.
35. Are we allowed ( go ) out with Tom ?
36. The teller was made ( raise ) his hands .
37. Mary was advised ( stay ) out of the crowd .
38. She prefers ( eat ) to ( prepare ) meals .
39. When the rainy season comes , you need ( repair ) the roof of the house .
40. The flowers need ( water ) but you needn’t ( water ) them now.