What other system does the circulatory system work with?

Which of the following was a characteristic of a dromaeosaur? modified front claw grasping with their forelimbs both a and b none of the above

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

There are fewer than 100 naturally occurring elements in the universe, but there are millions of different unified substances. explain how this can be true.