7. a) How does a vaccine relate to the virus that it protects against? (1 point) Will be marking brainliest!

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Which statement correctly describes other ways in which nebulae and stars are different? a. a star always has a higher density than a nebula. b. stars can form inside a nebula but a nebula can never be produced by any star. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star. reset submit

How does the human body lever work?