What gases are found only in the troposphere

From the perspective of an employee that effective channeling of work related information and concerns

By what factor does the drag force on a car increase as it goes from 65 to 110 km/h?

The gun from the crime scene shows tool marks where the serial numbers are ground off. there are also tool marks on the bullets left behind. what information can the tool marks on the bullets and gun provide about the crime? what type of evidence does this information provide, individual or class?