Your immune system protects against many______ agents. (infect)
举一反三
- Questions 19 to 21 are based on the passage you have just heard.19. A: The function of the human immune system. B: The cause of various auto-immune diseases. C: The viruses that may infect the human immune system. D: The change in people’s immune system as they get older.
- The innate _____ system is a universal and ancient form of host<br/>defense against infection.() A: sensitive B: horizontal C: optimal D: immune
- Your _________ system can remember how to fight a germ for the rest of your life. A: digestive B: immune C: defence D: urinary
- Your _________ system can remember how to fight a germ for the rest of your life. A: digestive B: immune C: defence D: urinary
- Which of the following system works together with the immune system?