阅读下面短文，从每题所给的 A 、B 、C 、D 四个选项中选出可以填入空白处的最佳选项。
In a small town lived Matthew, a diligent（勤奋的） youth with a passion for English. Nevertheless, he was completely 1 of the online world, leading him topav a heavy 2 in a case later.
One day, Matthew received an email from a stranger, claiming by 3 a special English learning material, he could easily improve his grades. The email also 4 several success stories, which convinced. Matthew. He followed the instructions and transferred much money to the sender's 5 . Receiving the material, he found it worthless. Matthew felt 6 and regretful, yet powerless.
However, the story didn't 7 there. After the setback, Matthew began to 8 the world of online scams （诈骗）. Discovering similar ones, he decided to use his English skills to expose them on social media, and 9 people to be watchful of online scams.
Matthew's story spread throughout the town. People expressed their 10 and support. With his assistance, many people escaped online scams. Everyone needs to 11 learn about relevant knowledge so as to enhance their awareness of 12 .
The Internet isn't without risks. When we 13 setbacks, don't give up. It's these experiences that make us more mature and cherish our 14 and privacy. Let's unite to establish a safe and 15 online environment!
