In the early 20th century and late 1900s; A complicated piece of legislation, it essentially gave preference to immigrants from Central, Northern and Western Europe, severely limiting the numbers from Russia and Southern Europe, and declared all potential immigrants from Asia unworthy of entry into the United States.
I hope this helped ://
Answer:
Radar
Explanation:
Radar technology employs the use of radio waves in determining the distances speed and location of certain objects. This was instrumental during the war as it helped countries foil secret attacks being planned.
It was used to operate anti-aircraft guns and was used on ships for easy navigation at night and to locate enemy ships and aircraft.
I think that the answer po this question is D
