The treaty of versailles was also known as

Treaty of Peace between the Allied and Associated Powers and Germany.

Both the Doolittle raid and the Battle of the Coral Sea were important because they were both a "first" for the US.

For example, the Doolittle raid was the first air raid to strike the Japanese homelands. On the other hand, Battle of Coral Sea was the first air-sea battle in the Pacific Theater between the US and Japan. Both of these events are critical in understanding how warfare changed during World War II.