When did the colorado river start to form the grand canyon

What is the initial population for each city? How do you know?

Social effects of flooding

What disease other than smallpox, Also infected European settlers? How was it spread?

From East coast to West coast in the United States, how many miles is it?

Explain how plate movement over the past 250 million years has created the present configuration of the oceans and explain in terms of rock types why the continents rise up further than the ocean floors.

Which of the following is (are) TRUE in plants? a. Mitosis occurs in gametophytes to produce gametes. b. Meiosis occurs in sporophytes to produce spores. c. The gametophyte is within the flower in angiosperms.

The Gibraltar connects what two bodies of water?

Estonia, Lithuania, Ukraine, Belarus, and Moldova once comprised Yugoslavia. True False

Where do most volcanos form A) In the ocean B) Over a hotspot C) At plate boundaries

Which of these is not an environmental effect of destroying wetlands A. loss of habitat B. increased air temperature C. poor absorption of rain water D. unfiltered water