Make the active sentences passive. HELP MEEEEEE

1. Franz Marc's painting The Waterfall was bought for five million dollars by a collector.

2. Some unusual sculptures were created by the artist.

3. The term "Impressionism" was invented by the art critic Louis Leroy.

4. Modern art isn't understood by many people.

5. The museum is visitted by lots of people every year.

6. The portrait wasn't shown by them.