Hey there!
When Columbia re-entered the Earth, the hot gases in the atmosphere (atmospheric gases), they destroyed the wings and it ultimately was destroyed. That technically means that the spacecraft wasn't shielded correctly, and led to a tragedy as well as major rethinking and reform for NASA.
That's why today, you see that all spacecraft are carefully tested and monitored before put into orbit.
Hope this helps!
Marco Polo traveled during the middle ages (AP period 3), for this the communication technology was not very advanced and Western Europe didn't really know the situation of East Asia and vice versa. When Marco Polo explained his travels to the Europeans of the greatness of China many Europeans decided to go and see for themselves if this greatness was indeed true. When the Europeans arrived in China they were very impressed and a new promotion of travel to China emerged, INCREASING China's economy.
Answer:
The Constitution provides that an amendment may be proposed either by the Congress with a two-thirds majority vote in both the House of Representatives and the Senate or by a constitutional convention called for by two-thirds of the State legislatures.
Explanation:
The answer is African Americans because the Civil Rights movement paved a way use for civil rights and liberties with their fights in the 60s, and it was led by Martin Luther King Jr. So I hope that help!