1, heap test, stop pouring into library B from the starting point, then move the library into library A to stop, then move forward from library B to the control line, stop pouring into library A, and move forward back to the starting point.
2. Through unilateral bridge, the left front wheel and the left rear wheel of the vehicle pass through the left unilateral bridge, and then the right front wheel and the right rear wheel pass through the right unilateral bridge. Large vehicles use second gear or above.
3. Turn around on the narrow road. When the vehicle drives to the U-turn section, stop at the right side, and lower its head when it does not exceed three advances and two retreats.