For example , the Kwun Tong Line 's alignment has changed for 2 times since its opening - the taking over of Tsuen Wan Line from Mong Kok to Central , and the taking over of Eastern Harbour Crossing section by the Tseung Kwan O Line . For example , the Kwun Tong Line 's alignment has changed twice since its opening â '' the taking over of Tsuen Wan Line from Mong Kok to Central , and the taking over of Eastern Harbour Crossing section by the Tseung Kwan O Line .