Title: Eritrea.
Question: What does the Constitution establish of all Eritrean languages?

Title: Uranium.
Question: What percentage of uranium in nature is uranium-235?

Title: Planck constant.
Question: According to Heisenberg and Schrödinger, the reduced Planck constant remains what?

Title: List of numbered streets in Manhattan.
Question:
At which Avenue do 21st and 22nd Streets begin?