Misc: the lowest string on a violin is in which key?

Questions

ball & ________?

In 1945, near the end of World War II, an important conference involving Truman, Churchill, & Stalin was held in this Polish city?

In Greek mythology, this person opened a box which contained all of the varieties of evil & set them loose on the world to afflict humankind?

Smart alecky, disrespectful,impertinent?

How many legs do crabs, lobsters & shrimp each have?