What controversial policy excluded Chinese immigration to America from 1882?

Chinese Exclusion Act

In "Destiny", what is the large spherical celestial body protecting the Last City on Earth? In Pokémon, which item increases capture rate and works best in the dark? Which artist released the 2004 hit song "Since U Been Gone"? Which character famously sings 'Smelly Cat'? What's an integer called if it's not divisible by 2?