Add a line to make it true

Question: How can you make the following true by adding a single line: .9 = 1.

Note: ≠ is not the answer.

Question: Why did the hen cross the road?

Question: What do you call a sad bird?

Question: What is an astronaut's favorite key on the keyboard?

Question: What is the tallest building in the world?

Question: What tastes better than it smells?