The shade over the window

Alaska and northern canada have a diet rich in vitamin d and their skin color is darker than predicted on the basis of iv intensity at their latitude. explain the observation:

The term used to describe a disease-causing microorganism isa. virus.b. infection.c. pathogen.d. microbe.e. bacterium.

Sediment layers stop lateral spreading when: they encounter a barrier they encounter an opposing current they run out of additional sedimentary material