19. bones are made flexible by a protein called collagen. they are made hard by chemicals known as calcium…

19. bones are made flexible by a protein called collagen. they are made hard by chemicals known as calcium salts. it is very difficult to break a bone; however, when one does break it can heal itself with time. calcium and collagen ______ bone strength.\na promote b engage\nc isolate d trigger

19. bones are made flexible by a protein called collagen. they are made hard by chemicals known as calcium salts. it is very difficult to break a bone; however, when one does break it can heal itself with time. calcium and collagen ______ bone strength.\na promote b engage\nc isolate d trigger

Answer

Brief Explanations:

El colágeno hace que los huesos sean flexibles y las sales de calcio los hacen duros. Ambos contribuyen positivamente a la fuerza de los huesos. "Promote" significa fomentar o contribuir positivamente, lo que concuerda con la relación de calcio y colágeno con la fuerza ósea.

Answer:

A. promote