阅读下面短文，根据所给情节进行续写，使之构成一个完整的故事。

On a bright, warm July afternoon, Mac Hollan, a primary schoolteacher, was cycling from his home to Alaska with his friends. One ofhis friends had stopped to make a bicycle repair, but they hadencouraged Mac to carry on, and they would catch up with him soon. As Macpedaled ( 骑行)along alone, he thought fondly of his wife and twoyoung daughters at home. He hoped to show them this beautiful placesomeday.

Then Mac heard quick and loud breathing behind him. “Man, that's a bigdog!" he thought. But when he looked to the side, he saw instantly that itwasn’t a dog at all,but a wolf:, quickly catching up with him.

Mac’s heart jumped. He found out his can of hearspray. With one hand on the bars, he fired the spray at the wolf. A bright redcloud enveloped the animal, and to Mac's relief, it fell back, shaking itshead. But a minute later, it was by his side again. Then it attacked the backof Mac'sbike, tearing open his tent hag. He fired at the wolfa second time, and again, it fell back only to quickly restart the chase（追赶）。

Mac was pedaling hard now. He waved and yelled at passing cars butwas careful not to show down. He was a steep uphill climb before him. Heknew that zxxk once he hit the hill, he’d be easy caught up and the wolf’steeth would be tearing into his flesh.

At this moment, Paul and Beeky were driving their car on their wayto Alaska. They didn’t think much of it when they saw two cyclists repairingtheir bike on the side of the road. A bit later, they spotted what they, too,assumed was a dog running alongside a man on a bike. As they got closer, theyrealized that the dog was a wolf. Mac heard a large vehicle behind him. Hepulled in front of it as the wolf was catching up fast, just a dozen yards awaynow.

注意：

（1）所续写短文的词数应为150左右；

（2）应使用5个以上短文中标有下划线的关键词语；

（3）续写部分分为两段，每段开头语已为你写好；

（4）续写完成后，请用下划线标出你所使用的关键词语。