Using suitable relative pronouns or adverbs

Using suitable relative pronouns or adverbs:
1.the man passed here about half an hour ago.he rode a red honda
2.the number of people will cause difficulties the airport.they will travel next week
4. The people didn't know French.he was speaking to these people
5. He can change the situation.he always likes to do something new
6.hoan kiem lake is historical place.it water is always blue
7. The mother was ververy sad. Her son was killed in an accident