In the rock cycle, which of these can directly undergo crystallization?

a. lava

b. sediment

c. igneous rock

d. metamorphic rock

Acivilization exists for several hundred yeaars, developing its own language. such a civilization probably has been: a. farming corn b. suffering from a lack of contact with the outside world. c. isolated by mountains or some other physical barriers. d. starving from lack of trade.

Which of the following is not a reason why shenzhen, china, is considered an emerging global city

Monk's mound in cahokia is an enormous earthwork very near to the mississippi river. what do archaeologists believe it was used for?