What was happening in history when this mutation took off in parts of Europe and Africa? Please help me with this song

Which describes radioactive decay of a substance

Look at the illustration of four letters from the american manual alphabet. decide whether the description of the letter is a good definition. if not, choose a counterexample. the letter i is formed by sticking up the smallest finger and folding all the other fingers into the palm of your hand with the thumb folded over them while keeping your hand still.

Climates are classified according to which two major factors: a. elevation and precipitation. b. latitude and temperature. c. elevation and latitude. d. precipitation and temperature.