What do scientists know about the dirtier of the universe

Read the article titled "castro resigns." why did the us impose trade sanctions against cuba in 1962?

Fossils of glossopteris, an extinct fern, were discovered on which continents to support the theory of continental drift? check all that apply.

In russia which of these challenges affects the transportation of both petroleum products and other goods? a poorly repaired roads b harsh weather and vast distances c frozen waterways d separatist movements