Misc: Fandible, lateral line, and dorsal fin are parts of a(n) ________.?

Questions

In 1986 Volcanic eruption in Cameroon releases poison gas, killing---------- . ?

In 1988 Cease fire between ---------- and Iraq takes effect after 8 years of war. ?

In 1988 Cease fire between Iran and ---------- takes effect after 8 years of war. ?

In 1988 Cease fire between Iran and Iraq takes effect after ---------- years of war. ?

In 1991 Communist coup is crushed in USSR in ---------- days. ?