Why is it almost impossible to commit a crime without leaving behind evidence?

techniques to find the culprit in a crime have improved,

yes its almost impossible to not commit a crime without leaving evidence, the people (police,etc) can use techniques to find your fingerprint, witnesses, footprint, and many other substances that belongs to the culprit. Witnesses can be a big help too. So yes its 'almost' impossible

succession returns a disturbed

ecosystem to a more stable state. this is also classified into two (2) types:

primary succession and secondary succession. the primary succession arises when

a new land is transformed and a bare rock has been exposed providing an environment

that can be occupied for the first time. while, secondary succession occurs

when a previously occupied environment was disturbed that kills much of all its

community

explanation: