I think its a , but double check because i dont want it to be wrong .
Answer:
Actin filaments return to their original positions (does not occur in muscle contraction, according to the sliding filament model).
Explanation:
B: between a nonmetal and a metal.
Answer:
Proteins, carbohydrates, nucleic acids, and lipids are the four major classes of biological macromolecules.
Macromolecules are made up of single units known as monomers that are joined by covalent bonds to form larger polymers.
Explanation:
The question is not complete, but luckily I could sneak the options.
The answer would be stomata allow plants to obtain certain minerals from the ground.
