Which of the following has not been important in the development of shenzhen as an sez? a. proximity to hong kong b. the socialist economic principles applied by the chinese government to its development c. state-of-the-art port facilities d. investment of overseas chinese in its development e. the fastest urban growth rate in human history

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.