How do soils form?
a. plants cement mineral particles together to form soil.
b. plants provide organic matter and minerals to make soil.
c. erosion transports mineral particles, and plants die and decay.
d. weathering breaks rocks into minerals, and plants die and decay.

Which of these statements is true about autotrophs, but not heterotrophs? a. they use sugar and oxygen to make carbon dioxide and water. b. they use chlorophyll and oxygen to make carbon dioxide and water. c. they use sunlight, water, and carbon dioxide to make sugars. d. they use sunlight, water, and oxygen to make chlorophyll.