Misc: what was the first really accurate timekeeper called??

Questions

In 1945 The Soviet Union invaded ---------- during World War II.?

In 1945 Eric---------- , guitarist, singer, born.?

In 1981 Pres. ---------- shot and wounded by John W. Hinckley Jr.?

In 1982 Third Space Shuttle Mission - ---------- returns to Earth.?

In 1984 U.S. ends participation in multinational peace force in?