______ voting is when a member of one party votes in another party’s primary.

The ozone "hole" was first discovered in the:

A. 1960s B. 1970s C. 1980s D. 1990s E. 21st century.

Proliferation optimists base their case on the assumption that

a. nuclear powers will eventually agree to eliminate their weapons. b. nuclear weapons would be no more destructive than modern conventional weapons. c. very few nations are likely to acquire nuclear weapons. d. nuclear weapons substantially raise the potential costs of war.