Had not the powerful US entered World War II, Russia would have been conquered by Germany. Russia had a much greater population than Germany, but its troops weren't as well trained and in the beginning of the war its equipment weren't as good.

No. Russia regained some land but, in the summer of 1942, Germany went on the offensive.

I know that but the Western allies kept Hitler from concentrating his forces against Russia. Also, the West through Arctic convoys gave Russia supplies. Finally, it was the West which bombed Germany not Russia.

No. In December 1941 when the US entered the war after Hitler foolishly declared war on the US, Russia had simply stopped Germany outside of Moscow.