Put the verbs in brackets in the correct form:
- If we become more aware of the environment , many diseases can [ prevent ] .....be prevented............ .
- In this region , the local language [ speak ] ........was spoken.......... a hundred years ago .
- There is a boat which [ leave ] ...is left....... the 7.30 A.M every day .
- According to the news , last week's concert [ raise ] ....was raised.............. $500 fore flood victims .
- Up till now , three public shelters [ build ] ......have been built........ around the town .