What grade am i in pl dont answer this is for a friend who needs points

Why did large numbers of african migrate to the americas

Why would the crystals in an intrusive igneous rock be larger than the crystals in a chemical sedimentary rock? a. intrusive rocks form beneath the earth's surface, so they cool very slowly, which produces larger crystals. b. chemical sedimentary rocks form from dissolved substances on the earth's surface with very high heat and cool very slowly, which produces smaller crystals. c. chemical sedimentary rocks and intrusive rocks have crystals of the same size. o d. chemical sedimentary rocks form deep in the earth, so they cool slower, which produces small crystals. € read question correct:

What is a small water source like a stream or brook?