Sure, here are the most appropriate words or phrases to complete the sentences:

1. The **expedition** to the North Pole was a failure because of bad planning.
2. As we **approached** the garden, we could see beautiful butterflies hovering above the flowers.
3. The book is about the many **immigrant** communities in the city and it describes their experiences of rebuilding their lives in a new country.
4. My flight is not **scheduled** to arrive until 8pm, so don’t come to the airport too early.
5. If we try to learn about and appreciate other cultures, we **broaden** our horizons.
6. He’s decided to sell his big house in the city and move to a little **cottage** in the country.

For the grammatically correct sentence:
F. A: **Are you coming** to the concert tonight?
B: Of course!