Misc: Of what country is Lagos the capital?

Questions

a canton is the ---------- field behind the stars?

a canton is the blue field behind the----------?

a ---------- atom in an atomic clock beats 9,192,631,770 times a second?

a cesium atom in an ---------- clock beats 9,192,631,770 times a second?

a full loaded supertanker traveling at normal speed takes at least ---------- minutes to stop?