Take my first and make it my last now I happened in the past

Question: Take my first and make it my last, now I happened in the past.

What am I?

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?