Which of the following processes can you infer is occurring in the sun, given its position on the Hertzsprung-Russell (H-R) diagram? A. contraction of the core only
B. expansion of the outer layer only
C. nuclear fusion only
D. contraction of the core, expansion of the outer layer, and nuclear fusion

new evidence is discovered.

oversights and errors are corrected,

new technology is applied to evidence.

on april 6, 1917, the u.s. joined its allies--britain, france, and russia--to fight in world war i. under the command of major general john j. pershing, more than 2 million u.s. soldiers fought on battlefields in france.