Put the verbs in brackets in the correct form: If we become more aware of the environment, many diseases can [ prevent ]

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