阅读下面短文，从短文后各题所给的四个选项(A、B、C和D)中，选出可以填入空白处的最佳选项。

    It was a cloudy day, and the terrible experience happened when I was studying in Bangalore. I got a call from my mom that my brother's1was fixed and they were arranging the wedding ceremony in the next few days.My 2was pretty far. So the next thing I was 3 to do was to book my 4 ticket as there was no direct flight to my hometown. The 5 was done by an agent in my neighborhood. I paid the whole amount 6. But when the day approached the 7 disappeared, leaving me without the train ticket, and thus 8all my travel plan.

    But as it is said, once you face such 9 situations, you realize your inner strength. I 10 decided I would complete my whole journey by bus. Without further 11， I took a bus to the first city stop. The next bus was again not 12 —it was 8 hours to a city near my hometown, where my aunt lived. They were also going to 13 my brother's wedding ceremony. So I called them and 14 them to accommodate me. They 15. Half the battle was won.

    Then next day, I was just a few hours from my hometown. When my aunt's family and I were boarding our car, my 16 asked me to switch places with her.

    The journey continued. We were trying to overtake(超越) another car when 17 a truck appeared in front of us and we went directly head on in front of it. We 18 with the truck. In this accident, almost everyone in our car was 19. Fortunately, I didn't have any injury, 20my cousin who switched places with me was seriously injured!

根据短文理解，回答下列问题。

    The Internet is becoming more and more important in our life. How much do you know about it? What is the Internet? The Internet is a large, worldwide collection of computer networks. A network is a small group of computers put together. The Internet is many different networks from (A)                 the world. These networks are called the Internet. Once you have learned to use the Internet, you can have a lot of interest in the World Wide Web.

    What is the World Wide Web?

    The World Wide Web has been the most popular development of the Internet. The Web is like a big electronic book with millions of pages. These pages are called homepages. You can find information about almost anything in the world on these pages. For example, (B) you can use the Internet instead of a library to find information for your homework. You can also find information about your favourite sports or film stars, talk to your friends or even do some shopping on the Internet. Most pages have words, pictures and even sound or music.

    What is e-mail? (C)电子邮件是给别人发送信息的一种方法。 It's much quicker and cheaper than sending a letter. If you want to send e-mails, you must have an e-mail address. This address must have letters and dots(点 ) and an ‘@’( meaning ‘at'). This is what an address looks like: Emily @ star. net. Write a message, type in the person's e-mail address, and then send the message on the Internet. People don't need to use stamps, envelopes or go to the post office since the invention of the Internet. Quick. easy and interesting--that's the Internet!

为验证Fe、Cu、Ag三种金属的活动性是依次减弱的，某化学兴趣小组设计了下图所示的四个实验．其中不必进行的是(    )