Misc: The poison-arrow frog has enough poison to kill about _______ people?

Questions

In 1981 Soyuz ---------- returns to Earth.?

In 1583 Thomas ---------- Day.?

In 1848 In Hawaii, the Great ---------- (division of lands) is signed.?

In 1875 Maurice ---------- (in Cibourne, France), composer (Bollero), born.?

In 1911 U.S. sent 20,000 troops to the ---------- border.?