describe the effects of cloud cover and particulate matter on the amount of solar radiation received at the earth's surface

What was apartheid and how did it restrict the rights of non-whites?

The amazon river is in africa true or false

If you were a casual recreational hiker with young children, which of the following trails would be least strenuous for a leisurely family outing? a. merced lake trail b. mirror lake loop trail. c. tenaya lake and tuolumne meadows trail d. el capitan trail