A geologist is studying an ancient stack of rock layers. Most of the layers contain fossils of shallow marine creatures (clams, corals,
etc.), suggesting the layers formed in a shallow ocean environment. But at the top of the stack, there is a layer that could only have
been deposited by a river.
What does this change in rock layers tell the geologist about Earth's history in the area where these layers formed? (Assume the
layers have not changed position since they formed.)

Fill in the blank 1. digestion occurs in the small intestine through the action of enzymes. 2. urea, excess water, and other waste materials are eliminated in a water fluid called 3. can cause infections by injecting dna or rna into hosts. 4. the human immune system produces in response to a vaccine, which later can bind to and destroy a pathogen if it invades. 5. are structures that link bone to bone at a joint 6. in the heart, blood flows from the right atrium to the right ventricle, where it is pumped to the the words i can use are: lymphocytes gliding pivot gas urine absorption dermis fulcrum lungs chemical viruses capillary vertebrae esophagus tendons antibodies synapses ligaments kidneys pathogens