【推荐2】Welcome

This course explores the concepts and algorithms (算法) at the foundation of modern artificial intelligence, diving into the ideas that give rise to technologies like game-playing engines, handwriting recognition, and machine translation. Through hands-on projects, students gain exposure to the theory behind graph search algorithms, classification, and other topics in artificial intelligence and machine learning as they incorporate them into their own Python programs. By course’s end, students emerge with experience in libraries for machine learning as well as knowledge of artificial intelligence principles that enable them to design intelligent systems of their own.

Requirement

CS50x or at least one year of experience with Python.

How to Take this Course

Even if you are not a student at Harvard, you are welcome to “take” this course for free via this OpenCourseWare by working your way through the course’s seven weeks of material. If you’d like to submit the course’s seven projects for feedback, be sure to create an edX account, if you haven’t already. Ask questions along the way via any of the course’s communities!

If interested in a verified (认证的) certificate from edX enroll at cs50.edx.org/ai instead.

If interested in a professional certificate from edX, enroll at cs50.edx.org programs/ai instead.

If interested in transfer credit and accreditation from Harvard Extension School, register at web.dce.harvard.edu/extension/csci/e/80 instead.

If interested in transfer credit and accreditation from Harvard Summer School, register at web.dce.harvard.edu/summer/csci/s/80 instead.

You are free to:

Share — copy and redistribute the material in any medium or format

Adapt — remix, transform, and build upon the material

【推荐3】The more you meditate and achieve mindfulness, the better you’ll feel. There are many free meditation apps that offer guided sessions, calming playlists.

This app is simple and approachable for meditation beginners. Most of the free sessions focus on teaching the users how to meditate and easing them into the practice, while also acknowledging that meditation can be difficult. Yet to get into the really good stuff, you need to pay for the full membership.

The app offers a multitude of meditation bells and calming musical notes during self-guided meditations. Featuring a variety of professional instructors and courses, Insight Timer also offers more contents for free users than other apps. Although the free option is extensive, the premium version (高级版) offers courses, downloadable meditations, night mode, and daily insights.

The app groups all its free meditations together, so it’s easy to use it without paying. These meditations run from 5 to 30 minutes and are available for download, a feature that other apps typically reserve for premium members. The number of free contents, however, is limited and included mostly basics. The design of the app is also relatively plain.

A nice feature about Breethe is the calming background music that plays while the app is open, even without opening a meditation or music. Breethe offers a lot of sleep contents, including visualizations and bedtime stories. The app does offer a few 7-day courses for free, but the majority (1,000-plus meditations) is locked behind the paywall.

【推荐1】Five Star Yellowstone Tour

Discover the world’s oldest national park, Yellowstone, on this grand wildlife tour. Our professional guides will give you a 5 star customer service experience on your all inclusive tour without any additional taxes or booking fees.

Starting at approximately 7 am, we will be rolling out the red carpet for you and all you have to do is to sit back and enjoy the ride. We provide snacks, bottled water, and cooked food for lunch. This tour’s main focus is on the wide variety of wildlife, Yellowstone’s rich historic landscapes as well as the fascinating prospect formed by the Yellowstone Supervolcano for over millions of years. Binoculars (双筒望远镜) are provided to help you appreciate the scenery better.

Whether you are an amateur photographer, a science or history enthusiast or just want to explore the outdoors, this tour has something for everyone. Our fun but professional guides will give you a first class tour in a very comfortable tour bus.

Duration: 10-12 hours

Taking Covid-19 safety measures: Click here

Hotel pickup offered

Group size: 9

Ticket type: Mobile

Available language: English

Scheduled date: Check availability

Total fees: $300 per adult (age 13-99); 40% discount (age 1-12)

Reserve now & pay later: Learn more

Free cancellation: For a full refund, cancel at least 24 hours in advance of the start date of the experience.

Now you’re all set! Have a great time.

【推荐3】Welcome to La Tomatina!

La Tomatina is a food fight festival held on the last Wednesday of August each year in the town of Bunol near to Valencia in Spain. Thousands upon thousands of people make their way from all corners of the world to fight in this world’s biggest food fight festival where more than one hundred metric tons of tomatoes are thrown in the streets.

At around 11 am, many trucks transport tomatoes into the centre of the town, Plaza del Pueblo. The signal for the beginning of the fight is firing of water cannons (水炮). Once it begins, the battle is generally every man for himself.

The fight lasts for nearly two hours. The cleaning process includes the use of fire trucks to spray down the streets. The authorities seem more concerned with cleaning the town that is a mess than cleaning the visitors, so some people find water at the Bunol River to wash themselves.

•Don’t bring bottles or hard objects as they can cause accidents and hurt other participants.

•Don’t tear others’ T-shirts.

•You must crush (压碎) the tomatoes before throwing to reduce the impact.

•When you hear the second shot, no more tomatoes can be thrown, otherwise there will be fines.

•Wear old clothes and shoes that you do not mind throwing away afterwards.

•Ensure you always have something clean to wipe your eyes with. You may find goggles (护目镜) useful.

•If you’re planning to take pictures, bring a waterproof camera!

•If you aren’t from Bunol, don’t forget to look for accommodation in advance.

Remember that you must have a ticket! No ticket, no entry. For more information about the official entry tickets, click here!