Which caused the US Army to take over the atomic research project being conducted at Columbia University in the early 1940s? the first atomic bomb test a letter from Albert Einstein Japan’s research into atomic bombs the US entry into World War II

The correct answer is D. The US entry into World War II

Explanation:

During the 1940s the Columbia University developed a project that focused on studying nuclear fission after this was discovered in 1938. This project began in the early 1940s and was sponsored by the United States Navy. However, in 1941 when the U.S. entered the war after the attack of Pearl Harbor the US Army took control over the project known as the Manhattan Project because at that moment the development of atomic bombs was related to the national security; also, the President Roosevelt considered the Army had more experience and abilities to develop this project.

assessment is the missing word

the perimeter of a triangle is 69 cm. side a is 5 cm shorter than side b. side c is twice as long as side a. find the length of each side. i need to know how to do it in 2 equations.  

equations:

a = b-5

c = 2a

a + b + c = 69