Sperm become capable of movement while in the .

Why do german shepherds shed so much

Why does the skin of your finger shrink when you wash clothes for a long time?

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?