In one sentence, describe what the following article is about: Go to http://worldenvironmentday.global/en and spend some time browsing the information provided there to see what's of most interest to you. You can read stories and news about the environment and learn how to participate in events. You can also use the site to register an activity that you, your school, business, workplace, or your community group are doing for WED. The great thing about registering your activity is that you can inspire others who learn about what you're doing. For example, in 2017, the theme was “Connecting People to Nature.” This theme encourages people to spend time in nature and appreciate the beauty and magnificence of the natural world. It also focuses on protecting the environment from harm. Also check out which country is the host country for WED for the year. For example, in 2017, Canada was the host country for WED. If you live in the host country, expect extra exciting activities to be planned! You might like to join in what has been planned, or even help out if you're early enough to sign up as a volunteer for the event. Check the WED website and do an internet search for WED events near you. The WED website is working to create the largest nature album in the world. Take a photograph or video of your favorite site in nature and post it to the album. For example, take a photo of your favorite lake or mountain range, create a video showcasing a lightning storm, or make a time-lapse video of cool clouds. Use Facebook, Twitter, Instagram, and other social media sites to promote WED. Share events in your area, quote environmental facts, add photos taken in nature, or give tips on living sustainably. Either way, spread the word to your friends, family, and followers that it is World Environment Day!
Summary: Visit the World Environment Day website. Find out what the WED environmental theme is for the year. Check out the activities that are already planned in your area. Add a photo or video to the nature album to share your favorite spot. Promote World Environment Day on social media.

Clean an empty mayonnaise jar with the label still attached, then fill it with yogurt. Take it to a public park or cafeteria and eat it enthusiastically by the spoonful. Glue on a Windex label or other cleaning product label. Spray it onto your car window or another object, wiping it off with a rag. Spray it into your mouth occasionally, while someone is watching. Using an actual Windex bottle is not recommended, unless you are certain it is thoroughly washed. Act as though you have nothing on your hand, eating, shaking hands, and so forth as normal. After one or more people have been watching you for several minutes, pretend to be surprised by the puppet, scream loudly, and run away with the hand puppet "chasing" you. This works with any unexpected object as well. Try searching thrift shops, antique stores, and yard sales for eerie-looking statuettes. Many pranksters have copied the visual style of signs found in subways, on telephone poles, or elsewhere, then altered the words or pictures to include silly messages. Be aware that placing these signs on property that isn't yours may attract the attention of police or employees, and is illegal in some locales. Pretend you are an incompetent spy, a time traveler, or a lunatic. For maximum confusion, begin by acting relatively normal, and drop increasingly bizarre hints about your "true nature." Here are example scenarios:  Dress in a futuristic, silver suit, or other sci-fi style. Act confused around everyday objects, for instance by smelling a mobile phone or attempting to get on a bicycle upside-down. Carry on an ordinary conversation, but include longer and longer pauses before your replies. Start giggling for no reason, then abruptly put on a serious expression and say "I need to return to the asylum now." and walk away backwards. It's easy to earn a few confused glances, but with extra effort, you can transform them into laughter and applause — without sacrificing the confusion, of course. Here's some advice to get you started:  For a public comedy sketch, begin with one person dressed in a bizarre costume or doing something unusual, attracting attention while pretending that nothing is unusual. After a few minutes, have one or more other characters show up and talk to the first person loudly.  Organize a flash mob to rush in on a certain location and dance, sing, or perform another communal activity. Check Improv Everywhere for upcoming events you can join in your area.
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One-sentence summary -- Fill a mayonnaise jar with yogurt. Fill a spray bottle with blue sports drink. Walk around wearing a hand puppet. Post fake signs in public. Act as though you have a poorly-kept secret. Plan a public sketch or flash mob.

Problem: Article: OS X Mavericks (10.9) has a lot of problems with sound, many of which were fixed in Yosemite (10.10). El Capitan (10.11) has fixed even more of these problems. Mac updates are free and are available from the Mac App Store. If there are any available system upgrades, they'll be listed here. Download El Capitan if it is listed in the Updates section. The download will likely take a while to complete. Follow the prompts to install the system update. It's a pretty straightforward process, and you won't lose any of your files or settings. Once the update has finished and you're back at your desktop, test your sound again to see if it is working.
Summary:
Check to see if you are running the latest version. Open the Mac App Store. Click the "Updates" tab. Download the latest version of OS X. Install the system update. Test your sound again.