Uranium-238 is found only in igneous or volcanic rocks. They can date a very ancient fossil also but carbon cannot date and ancient fossil. Trees are not very ancient. Carbon-14 can be used to measure only fossils of recent age.
Answer:
Villi, alveoli and nephrons are similar as :-
B. They provide large surface areas for molecular exchange.
A. beneficial its wouldn't be harmful cause antibiotics is a bacteria killer so its beneficial
