Mac was pedalling along the mountain road when he saw a wolf chasing him, opening its bloody mouth.     1     (他的恐惧无以言表). He     2     (乞求路过的司机帮助他), but in vain. So he got off his bike without hesitation, seized it and threw it at the wolf with all his strength,    3       (尽力把狼吓走). He was about to become the food of the wolf when his friends joined him. When     4     (向朋友描述这件恐怖的事情), he still felt as if his hair had stood on end.