3. Which structure protects the developing embryo of a beech tree? A. cotyledon
B. cuticle
C. seed coat
D. stomata

Consider the model of the oxygen cycle on earth. the majority of earth's oxygen reservoirs are found in the a) atmosphere. b) biosphere. c) hydrosphere. d) lithosphere.

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils

Explain how scientists use geologic time to determine the age of landforms.