In the hills of north carolina, several different species of wrens live in one large pine tree. this is possible because the wrens a) must have the resource competition from the other wren species. b) eat different foods found in and on the tree. c) have different natural enemies. d) breed at different times.

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

Substances that can pass through cell membranes by diffusion include a. na ions. b. proteins c. glucose. d. oxygen.

Pl as time goes by and water goes through the water cycle again and again, the amount of water on earth: increases decreases ostays the same goes up and down