#1 should be your answer!
Filtered blood leaves the kidney through the renal vein and flows back to the heart. Pee leaves the kidneys and travels through the ureters to the bladder. The bladder expands as it fills.
Up to 30,000 kelvins (or 53,540 degrees Fahrenheit)
The amu (atomic mass unit) of a proton and neutron are equal. The amu of the electron is significantly smaller than these.
