From approximately 240 to 66 million years ago, dinosaurs dominated most of the land habitats on Earth. Around 66 million years ago, most dinosaurs went extinct when an asteroid struck the Earth. Mammals, which were much smaller and lived primarily in underground habitats, were able to avoid extinction. Mammals then underwent an adaptive radiation to develop a wide variety of new species.

Ineed to get this test done which of the following statements is correct in hour our immune system responds to a potential pathogen? a.) the skin will be the first line of defense, and then the many phagocytes in the bloodstream will attempt to consume the possible pathogen. b.) b cells will start reading the antigen code immediately and call t cells to assist in destroying the pathogen. c.) the adapted immune system will call on the innate immune system to destroy the pathogen. d.) the t-cells in the adapted immune systems are the first to recognize the pathogen