How much of a radioactive element becomes stable in a half life?

How did the movement of soldiers during world war 1 contribute to the global influenza (flu) pandemic of 1918 to 1919, which killed millions of people

Which season occurs in the northern hemisphere when the sun is at its lowest point in the sky

When the soviets created the borders of their central asian and caucus republics, the paid little attention to where each region’s ethic group lived. ethnic-related disputes exist along every sherd boundary in central asia. true false