1.They must finish the work in a work.__________________________
2.We should water the tree as often as possible.________________
3.The workers can build the hospital in three months.___________
4.The farmers may harvest rice three times a year._______________
5.Knock a strong stick into the earth next to the hole.__________
參考答案:1.The work must be finished by them in a work.
2.The tree should be watered by us as often as possible.
3.The hospital can be built by the workers in three months.
4.Rice may be harvested by the farmers three times a year.
5.A strong stick is knocked into the earth next to the hole.
