—– was defeated at Dien Bien Phu in 1954

According to your text, two reasons for migration into the United States by the 1990s included

When did children start to do “duck and cover” drills in school?

In 1985 —– came to power in the Soviet Union

—– was elected U.S. President in 1972. (Full name.)

The Big Three Allies included —–. (Countries, DO NOT ABBREVIATE.)

Elastic materials are capable of recovering shape after deformation

The characteristic of a sound wave that you interpret as loudness is related to 

Define a wave.  Ensure to include the properties of identifying a wave which were covered in the lecture.

A sonar signal is sent from an oceangoing ship, and the signal returns from the bottom 1.75 s later. How deep is the oceanbeneath the ship if the speed of sound in seawater is 1,530 m/s?