Why do you need to pull the handbrake for 3 seconds when starting on a slope?

[StAthena]

When the slope is relatively steep and the vehicle is heavy, the car will roll backward if the brake is not applied. Here is the relevant introduction: 1. Reason: If you use your foot to brake, there will be no foot to press the accelerator, and releasing the clutch will cause the engine to stall due to insufficient power. In such cases, it is necessary to pull the handbrake, which is safe and simple to operate. 2. Hill start: Hill start is a field test in the second subject of the driver's license test, which involves starting a vehicle parked on a steep slope upwards. The second subject test items include: stopping and starting on a slope, parallel parking, curve driving, right-angle turning, and reversing into a garage. The second and third subject tests are conducted in a combination of mandatory and optional items, with optional items randomly selected based on different vehicle types. Among them, the hill start is a mandatory content and can only be conducted after passing the stake test. Moreover, if the hill start is not passed, the following items in the second subject cannot be conducted.