Which of the following adaptions helps birds fly a: they have more fat than most animals so they can fly for long distances
b: they have hollow bones so they are lighter
c they have a smaller blood vessel so
their heart have to work less in a flight
d: the largest stomach so that they can absorb food faster

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