1 Turn right 40 degrees for the first time and turn left 40 degrees for the second time. Result: Same direction.

First turn right 40 degrees, second turn left 140 degrees.

First turn left 40 degrees, second turn right 140 degrees.

Turn left 40 degrees for the first time and turn left 140 degrees for the second time. Result: In the opposite direction.

Among them, after two turns, the driving direction is parallel to the original direction (a)