What is d inner layer of a mollusca shell called?

Hey me with this one❤❤❤❤ every organism needs food. does a cell also need it? explain very briefly.

Which of the following can be reduced by the use of renewable energy sources? a. social costs b. economic costs c. environmental costs d. all of the above select the best answer from the choices provided a b c d

What substance is the most acidic. lemon juice. tomato juice. sodium hydroxide. water