(填空题)please match the correct descriptions. inserting the needle with the aid of the finger of the pressing hand（） gripping and inserting the needle（）Inserting the needle by pinching the skin（） inserting the needle by stretching the skin（）甲，pinch up the skin between the thumb and index finger of our left handB， suitable for areas with loose skin or fat padC， insert the needle into the skin close to the edge of the nail of the pressing handD，use the thumb and index finger of our left hand to grip the lower portion of the needle