A.mysterious B.ridiculous C.fascinating D.apparent40（）……

Behind our house is the start of a fascinating trail (小径). This trail is one of the old roads that wind through untold miles of forest. My (36) , Beans, and I walk the trail frequently. Normally, Beans sniffs alongside the trail to follow the smell of a deer track or explore some cause known only to him.
Beans is a white dog, quite handsome and very smart. He not only understands what we tell him, but also often makes sounds as if he were trying to (37) back.
One morning, we took a different route, which led us to an unfamiliar trail. I was sure this trail would eventually lead us to our familiar (38) . But, no. We seemed to be far off course. After two hours, I suddenly realized that Beans probably (39) the way home. So I urged, "Beans, take me home." He ran down a new trail. But it merely led to an intersection (岔道口) of trails.
Soon it became (40) that we were getting nowhere. I began to picture the rest of the day in the (41) , without food or drink. We had walked about ten miles. But Beans seemed totally (42) The sniffing and exploring was going well for him.
Finally, we (43) a crossroad near a highway. Lady Luck suggested I should turn left. We did and (44) reached a cottage beside a field. I knocked on the door and explained my situation to an old man. He laughed and then drove us home.
Since our adventure, I (45) that Beans probably knew all along how to get home.
He was just having too much fan exploring new trails.

A.mysterious 
B.ridiculous 
C.fascinating 
D.apparent