What groups provided labor to build this
transportation system?

The Chinese laborers worked out well and thousands more were recruited until the railroad's completion in 1869. Chinese labor provided the massive labor needed to build the majority of the Central Pacific's difficult railroad tracks through the Sierra Nevada mountains and across Nevada.

Explanation:

explanation:

there are two statements that are incorrect.

1. the marshall plan was a lend lease program. it was an economic plan that europe redevelop itself after wwii.

2. einstein didn't really do anything to further the allied cause in building the bomb. he merely sent a letter to fdr telling him (in 1939) that if the united states entered the war, perhaps it would be wise to build the bomb before germany did. i would say this answer is incorrect, but when america entered the war 2 years later, fdr thought it might be a good idea to take einstein's advice.

the 4th choice is definitely so wrong that is likely the single answer of this question

people can eat food during that time