Secondly, the left palm is straight, the back of the hand is placed in front of the left palm to the right, the right thumb and forefinger are held in a circle, and the other three fingers are naturally held in a circle with the forefinger, and then the circle held by the right forefinger and thumb is close to the left palm. This action stands for "addition"

Furthermore, when the left hand is not used, the thumb and little finger of the right hand are extended, and the other three fingers are bent on the palm to imitate the shape of the oil pan. Thumb down, little finger up, back of hand towards yourself. Turn the whole hand in a small circle, imitating the posture of pouring oil, representing "oil"

Finally, you don't need your left hand, put your right hand in front of you, put your palm flat, hand down, back up, and translate from bottom to top until you touch your chin. This action stands for "full"

The above four movements, people who know sign language know at a glance that they mean "fill up the car"