Answer to this question is b
Answer:
question 1 is 4. question 2 is 2. question 3 is 1. question 4 is 2. question 5 is 1=3 2=2 3=4 4=1. question 6 is 2
Answer:
it affects the hardness of the shells because calcium has a high reactivity which causes the shell to be hard
Explanation: