imagine you are a detective examining a crime scene you are trying to identify the person who committed the crime so you collect many samples at the crime scene which sample would be most useful in identifly the person who commited the crime A. a book found on the ground at the crime scene B. a pair of shoes found at the crime scene C. an uneaten burger and fries left at the crime scene D. a piece of fingernail found at the crime scene

an organism's phenotype is the  form of a trait  that it  displays. for  flowercolor, a pea  plant  can  display  a phenotype of purple or white flowers. an organism's  genotype  is the alleles of a gene it contains. based on his data, mendel concluded that a phenotype can be  determined  by more than one  genotype.

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.