Read each sentence. Circle each word in which oo stands
for the vowel sound you hear in too. Underline each word
in which oo stands for the sound you hear in look.

What evidence supports geological processes changing the surface of the earth? cutting down forests creates a decrease of habitats. tectonic plates uplift the rocky crust of earth to form mountains. competition in ecosystems creates a decrease in diversity. pollution runoff contaminates a lake.