阿暐看到某網頁在介紹在北半球如何利用立竿見影法來判斷方位，網頁中的說明如下： Step1：Hold up a stick. Step2：Mark the endpoint of shadow with a stone A. Step3：Wait 15 minutes while the shadow moves. Step4：Mark the new endpoint of the shadow with a second stone B Step5：Draw a line between the two stones. Which direction does the question mark refer to? 請問空格中分別應填入什麼方向？