WEBTODAYZ

More than 52 percent of the world's population is under 30 years old. According to the United Nations Educational, Scientific, and Cultural Organization (UNESCO), as of 2012, 50.5 percent of the world's population were people under the age of 30. Around 89.7 percent of those young people live in emerging and developing economies like the Middle East and Africa.

There are only three countries in the world that don't use the metric system. For simplicity's sake, most of the more than 200 countries in the world use the metric system when describing things like length or mass. However, there are three countries that stand out: Liberia, Myanmar, and the United States. And soon, that number might be down to two. In 2018, Liberia commerce and industry minister Wilson Tarpeh said the government plans to adopt the metric system in order to promote accountability and transparency in trade, according to the Liberian Observer.

The red-billed quelea is the most common bird on Earth. There may not be any red-billed queleas in your neighborhood, but that's not because there aren't an abundance of them. These birds, which live in sub-Saharan Africa, are considered "agricultural pests" because their massive flocks can obliterate entire crops. Although their numbers fluctuate, there are around 1 to 10 billion queleas, which leads scientists to believe that there are more of them than any other bird on Earth, according to Audobon.

There are 41 countries that recognize sign language as an official language. There are estimated to be 72 million deaf people around the world. There are also about 300 different sign languages—including American Sign Language and International Sign Language—as well as 41 countries that recognize them as an official language

Facebook has more users than the population of the U.S., China, and Brazil combined. Do you use Facebook? If you don't, you're among a number that gets increasingly smaller every day. In fact, 2 billion active users have an account on the social media platform, which is more than the population of the United States, China, and Brazil combined. Facebook's co-founder and CEO Mark Zuckerberg posted about the milestone, saying, "We're making progress connecting the world, and now let's bring the world closer together."

There are only two countries with names that begin with "The." You might find yourself saying "the" before various countries and place names when referring to them thanks to grammar and common pronunciation, which is why we say the United States or the Maldives. However, only The Gambia and The Bahamas formally include "the" in their nation's names.

The oceans contain almost 200,000 different kinds of viruses. The next time you feel like taking a dip in the big blue ocean, you might not want to think about the fact that the seemingly pristine water is home to almost 200,000 different kinds of viruses. While this may sound scary, Matthew Sullivan, a microbiologist at the Ohio State University, told CNN, "Having that road map [of what viruses exist] helps us do a lot of the things we'd be interested in to better understand the ocean and, I hate to say it, but maybe to have to engineer the ocean at some point to combat climate change."

Copenhagen is the most bike-friendly city in the world. Many places around the world are trying to figure out how to rework their infrastructure to accommodate cyclists and hopefully, in turn, encourage residents to use the environmentally friendly mode of transportation. That's why Copenhagen has become such a role model; according to Wired, it's the most bike-friendly city in the world.