Convert 4 tacks/brick to rivets /block, given: 12 bricks = 7 stones
5 stones = 3 blocks
6 bricks = 9 shingles
3 tacks = 2 rivets

Ais stronge

Ithink carbon dioxide, i am not completely sure.tell me if i am wrong.

Muscle fiber i think that i right

According to arrhenius theory of acid and bases, an acid is a proton donor, while base donates hydroxyl ions. further, acid and base reacts to form salt and water.consider following example.hcl    +      h2o          →      cl-          +      h3o+here, hcl has donated a proton, hence it is an acid.now consider following reactionhcl      +      naoh            ↔      nacl      +        h2oin this reaction, hcl donates proton, hence it is acid. on other hand, naoh donates hydroxyl ion (i.e. hence it is a base.