9. C
10. C
11. A I believe
12. D
In March 1917, the army barracks at Petrograd united striking workers in challenging socialist reforms, and Czar Nicholas II was enforced to step down from his leadership. Nicholas and his family were first detained at the Czarskoye Selo palace, then in the Yekaterinburg palace near Tobolsk. In July 1918, the improvement of anti-revolutionary forces caused the Yekaterinburg Soviet forces to fear that Nicholas might be set free. After a secret meeting, a death sentence was approved on the imperial family, and Nicholas, his wife, his children, and several of their servants were gunned down on the night of July 16.
Americans got involved in the Korean War in the 1950s decade. This was because they feared that more countries may become communist, especially Korea. Hope this helps. Please rate, leave a thanks, and mark a brainliest answer. (Not necessarily mine). Thanks, it really helps! :D