The Appalachian Mountains were formed when ________ and ________ collided more than 250 million years ago
A) North America; Africa
B) Africa; Europe
C) South America; Africa
D) Australia; Asia
Answer: A
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A fault surface is also called a ____
A)dip B)strike C)fault plane D)fault fracture E)fracture plane
The group of vertebrates with the most species, that is, the most diverse, in the sea is ________.
A. mammals B. fish C. birds D. reptiles E. amphibians
When a solution of ammonium chloride, NH4Cl, is added to a solution of lead(II) nitrate, Pb(NO3)2, a white precipitate of lead chloride, PbCl2, forms. Which of the following is the net ionic equation for this reaction?
A) 2 NH4Cl(aq) + Pb(NO3)2(aq) ? PbCl2(s) + 2 NH4NO3(aq) B) 2 NH4+(aq) + 2 Cl-(aq) + Pb2+(aq) + 2 NO3-(aq) ?PbCl2(s) + 2 NH4+(aq) + 2 NO3-(aq) C) Pb2+(aq) + 2 Cl-(aq) ? PbCl2(s) D) Pb2+(aq) + Cl22-(aq) ? PbCl2(s)
Which is the most important molecule in the ecosystem?
A) oxygen B) nitrogen C) salt D) lead E) water