On This Day: 24 April 1970 ---------- becomes a republic within the Commonwealth ?

Questions

--------------, in Russia, is the largest city north of the Arctic Circle.?

Myanmar was known as ------------- until 1989.?

Each tour through Natural Bridge Caverns in ------------ covers 3/4 mile. An average tour guide will walk almost 560 miles in one year.?

------------------- is the only Central American country not bordering the Caribbean Sea.?

--------------- use wooden "eyeglasses" with narrow slits for eyepieces to protect their eyes from glare reflected by ice and snow.?