Your DNS cache (域名存储器) stores the locations (IP addresses) of web servers that contain web pages which you have recently viewed. If the location of the web server changes before the entry in your DNS cache updates, you can no longer access the site.
If you encounter a large number of HTML 404 error codes, you may need to clear your DNS cache. After you clear your DNS cache, your computer will query(询问) nameservers (域名服务器) for the new DNS information. The following methods allow you to remove old and inaccurate DNSinformation that may result in 404 errors.
Windows 7
To clear your DNS cache if you use Windows 7,perform the following steps:
Click Start.
Enter cmd in the Start menu search text box.
Right-click Command Prompt and select Run as Administrator.
Run the following command:
Ipconfig/flushdns
If the command succeeds, the system returns the following message: Windows IP configuration successfully flushed the DNS Resolver Cache.
Windows® 8
To clear your DNS cache if you use Windows 8, perform the following steps:
On your keyboard press Win+X to open the WinX Menu.
Right-click Command Prompt and select Run as Administrator.
Run the following command:
Ipconfig/flushdns
If the command succeeds, the system returns the following message:Windows IP configuration successfully flushed the DNS Resolver Cache.
Windows XP, 2000, or Vista®
To clear your DNS cache if you use Windows XP, 2000, or Vista®, perform the following steps:
Click Start.
On the Start menu, click Run.
If you do not see the Run command in Vista, enter run in the Search bar.
Run the following command:
ipconfig/flushdns
If the command succeeds, the system returns the following message: Successfully flushed the DNS Resolver Cache.
MacOS® 10.10.4 and above
To clear your DNS cache if you use MacOS X version 10.10.4 or above, perform the following steps:
Click Applications.
Click Utilities.
Click Terminal.
Run the following command:
sudo killall-HUP mDNSResponde
If the command succeeds, the system does not return any output(输出信息).
Warning:
To run this command, you must know the computer‘s administrator account password.
1. If the command succeeds, all the following systems return a massage except .| A．Windows® 8 | B．Windows 7 |
| C．Windows XP, 2000, or Vista® | D．MacOS® 10.10.4 and above |
| A．To introduce something about several systems on computer. |
| B．To explain how to solve some problem in several systems on computer. |
| C．To explain how to access some sites in several computer systems. |
| D．To explain how to install DNS cache in several computer systems. |
| A．DNS cache stores the IP addresses of web servers. |
| B．DNS cache needs to be cleared, if you meet a large number of error codes. |
| C．DNS information may result in 404 errors. |
| D．Unless the entry in your DNS cache updates, the location of the web server won‘t change. |
相似题推荐
【推荐1】It’s exciting when your teens announce a dream of being a writer. However, besides providing them with different kinds of reading materials, you can direct them to the following websites offering great resources to future storytellers.
Figment
This is an online community and self-publishing platform for young writers. Users can not only “publish” and read short stories, poetry, lyrics (歌词), essays, and novels on it but also review, react to and comment on works from other users. Sometimes, Figment offers writing contests to help young writers improve their skills.
Wattpad
It is described as “the YouTube of writing”, because it allows amateur(业余的) creators to share their works with others. It claims to have more than 90 million users. Well-known writers, such as Margaret Atwood and Cory Doctorow, even post their works here.
Teen Ink
Supported by the non-profit Young Authors Foundation, Teen Ink has offered teens the opportunity to publish their creative works and express opinions on issues that affect their lives for over 31 years. Teen Ink has no staff writers or artists. The magazine and website are devoted entirely to writing, artworks, and photos by teens. It’s also a good platform for teens interested in writing and publishing non-fiction essays and articles, as well as poetry.
Tumblr
The microblogging platform is a wonderful place for bold self-expression, but it is also suitable for young literature lovers and bookworms. Tumblr optionally allows users to raise questions about the blog, and it also offers a “fan mail” function, so users can send messages to those bloggers they like.
1. Which of the following organizes writing competitions for users?| A．Figment. | B．Wattpad. | C．Teen Ink. | D．Tumblr. |
| A．It encourages bold self-expression. |
| B．It is a newly-founded platform for teens. |
| C．All the works on it are provided by teens. |
| D．There are many famous writers sharing their works on it. |
| A．publish their own novels. |
| B．communicate with other bloggers. |
| C．read short stories, poetry, lyrics and essays. |
| D．express opinions on issues that affect their lives. |
Third-generation mobile phones, known as 3G, are the next big step for the telecom industry. Data speed in 3G networks is much quicker than that in present technology. This means users can have high-speed Internet access and enjoy video and CD-quality music on their phones.
“Mobile data is not a dream; it’s not an option but a requirement,” said Len Lauer, head of a US communications company, Sprint PCS, at a 3G conference in Bangkok earlier this month.
With 3G, you can forget about text messages telling you yesterday’s news; a 3G phone can receive video news programs, updated four times a day. Internet access will also be much quicker, making it easier to surf the Web on your phone than on your computer at home.
Face-to-face video calls
Don’t worry about getting lost. 3G phones offer map services so you can find a new restaurant just by pressing a few keys on your handset.
However, the most impressive part of 3G technology is video calling. With live two-way video communication, you can have face-to-face talks with friends and family on your mobile phone.
Many European countries have already launched the service. In May 2000 the US Government issued five license to run 3G wireless services, while the first 3G phones arrived in Italy in March this year.
International telecom companies can’t wait to sell 3G in China, the world’s largest mobile telecommunications market. But they will have to be patient. At the moment, China is busy testing its 3G-based technologies, networks and services. This will be followed by a trial period before the phones can finally hit the shops.
“We need to create a pool of 3G customers before the large-scale commercial launch of the service,” said Fan Yunjun, marketing manager for Beijing Mobile. “We expect that the 3G licenses will be seen late next year.”
| Third-generation mobile phones (3G mobile phones) | |
| A. Data speed: B. Video and C. Video news programs: D. Internet access: quicker and | |
| Impressive functions | A. Offer B. Provide two-way video |
| 3G phones in China | A. China is busy B. 3G phones should go through a C. 3G phones are expected to be seen |
【推荐3】With the new semester about to start, our school is welcoming a group of new international students. We have some apps here with an English version that will make your life easier. We hope you will have a wonderful life here.
WeChat is now the most popular social media app in China. Almost everyone is using WeChat. You can send both text and voice messages on WeChat. You can also make voice and video calls. You can also post texts, pictures and video clips. If your friends in your home country have this app, you can also chat with them through voice or video. WeChat is also widely used now as a form of payment which can be used in stores, online, and in other shopping apps.
★Alipay
Alipay is a similar app to PayPal. It was first used on Taobao and now people can use it as a mobile payment option. You can even use mobile payment at street vendors, so if you have this app, you can leave your wallet at home.
★Didi
Now Didi seems to be the smartest way to travel around. With one tap, a car comes directly to you. Didi is a Chinese car-hailing service app. It has a function called “ride sharing”, which saves a lot of money for passengers, but it does not have an English version, so if you want to use it, you will have to learn some Chinese.
★Pleco
This is one of the top Chinese/English dictionary apps and it covers 130,000 Chinese words and includes 20,000 example sentences with pinyin. It is perfect for those who want to learn Chinese, and also for tourists who need to translate words or phrases from English to Chinese.
1. Alipay was originally developed to ________.| A．pay for a car-hailing service |
| B．compete with WeChat in payments |
| C．be used on online shopping website Taobao |
| D．be convenient for people who leave their wallet at home |
| A．learn some Chinese | B．know how to use WeChat |
| C．have a passenger to ride with | D．download an English version app |
| A．Didi. | B．Pleco. | C．WeChat. | D．Alipay. |
