How does the immume system defend your body?

Are these strong bases, neutral, strong acids, weak acids or weak base household bleach (ph=12.6) fluid in a car's battery (ph of less than 1.0) milk (ph=6.7) stomach contents (ph=2.2) pure water (ph=7)

How energy flows through each level in this energy pyramid. is all the matter and energy from one level transferred to the next level?

How do water’s relative densities as a solid and a liquid differ from that of most other substances? water’s solid and liquid forms have different densities, while most other substances have solid and liquid forms with similar densities. water’s solid and liquid forms have similar densities, while most other substances have solid and liquid forms with different densities. water’s liquid form is less dense than its solid form, while the opposite is true of most other substances. water’s solid form is less dense than its liquid form, while the opposite is true of most other substances.