What is the term for the pattern of spiral impressions inside a handgun?

a) rifling
b) ejector markings
c) lands and grooves
d) extractor markings

Ineed extreme for task 2. my student number is 571721. many to whoever solves this correctly, im in debt to you.

What are chlorofluorocarbons and what impact do they have on the atmosphere?

20. threshold braking in the vehicle's braking system occurs when a. the brake pedal is pushed, heel on floorboard, with full foot pressure. b. the brakes are exerting full braking power, without traction loss. c. the driver begins pushing down the brake pedal, with moderate slowdown. d. the brakes just begin to take hold with a gradual slowdown.