A tortoise challenges a hare to a race.The hare eagerly agrees and quickly runs ahead,leaving the slow-moving tortoise behind.Confident that he will win,the hare stops to take a nap.Meanwhile,the tortoise walks at a slow steady pace for the entire race.The hare awakes and runs to the finish line,only to find the tortoise already there.Which of the following graphs matches the description of the race,showing the distance d traveled by the two animals over time t from start to finish？（　?。?br />一只烏龜向一只兔子挑戰(zhàn)比賽。兔子欣然同意并迅速跑到前面，把動作緩慢的烏龜留在后面。兔子自信地認為他會贏，所以停下來小睡了一會兒。與此同時，烏龜以穩(wěn)定的步伐走完了整個比賽。兔子醒來并跑到終點，只是發(fā)現(xiàn)烏龜已經(jīng)到那里了。以下哪個圖形描述了比賽的描述，顯示了兩只動物從開始到結(jié)束在時間t內(nèi)走過的距離d？（　　）