3 . Most of our 400 national parks and historic sites are free, and even the ones that aren't offer several free days during each year. And don't forget admission and tours are free at all our state capitol buildings. So, pull out a map and start planning to find out your destinations.

California: Jelly Belly Factory

Who doesn't like Jelly Bellies? Free tours of the Jelly Belly Factory are offered daily at 1 Jelly Belly Lane in Fairfield, California. Free samples, too! Can't decide which flavor to try first? Check out our ranking on the best jelly bean flavors.

Colorado: United States Air Force Academy

Driving around and taking in the spectacular natural beauty of Colorado is, of course, free. If you know some kids who might be interested in becoming a future cadet, then head to the United States Air Force Academy, just outside Colorado Springs, where free tours are offered daily.

Connecticut: Yale University

New Haven, Connecticut was the first place in the U.S. to offer pizza by the slice to hungry customers, including students of a little college called Yale University. While in New Haven, you can go on a tour of the campus, free of charge, every day of the week. It's the Alma mater(母校) of both President Bushes, Bill and Hillary Clinton, journalist Bob Woodward, and Samuel F.B. Morse, inventor of the Morse code to name a few. Make sure you check out the best state gifts from each state while you're at it.

Florida: Beaches

From the spectacular sunsets in Key West, the southernmost point in the U.S. mainland, to strolling the streets way up north in historic and charming Fernandina on Amelia Island, Florida is chock full of free beaches to enjoy.

4 . How to protect your hearing

All sounds that are louder than 85 decibels(分贝) — from industrial machines to heavy traffic and loud music — are a threat to your hearing, especially if your exposure is long or repeated. That’s because loud sounds can injure or destroy hair cells in your inner ear that are involved in sending sound signals to your brain.

    1     . Since most of us don’t carry decibel meters around, you can rely instead on this rule of thumb: if you are required to raise your voice to be heard by someone standing an arm’s length away then there’s potential for harm. Ideally, you can reduce the noise, go to a quieter environment or wear protection such as earplugs.

    2     . Many smartphones can produce sounds of 100 decibels or more. Some will warn you when you exceed safe levels. If yours doesn’t, keep it set to less than the maximum volume.

Deafeningly loud noise is not to blame for all hearing loss, though.     3    . In addition, the inner ear can also become worse as you get older, and unfortunately, there’s no real way to prevent this.

If you suspect you’ve lost some hearing, see a GP or audiologist.     4    , particularly when it’s a question of picking up people’s speech.

The technology itself “can take a while to get used to because your brain needs to readjust,” says audiologist Dr. Gemma Twitchen. “    5     , when you first notice it reducing.” Hearing aids are improving in terms of comfort, sound quality and appearance — there are now tiny, barely noticeable models available.

7 . When Clara Harlowe Barton was 11 years old, her older brother was seriously injured in a fall. Barton spent two years nursing him back to health until he fully got well. Although she had this early nursing experience, Barton would not work as a nurse until later in life.

At the age of seventeen, Barton worked as a teacher in Massachusetts. Twelve years later, she opened the first free public school in New Jersey. The school grew from only six students on the first day of classes to more than 200 students by the end of the school year. When the school opened in the fall of 1853, Barton was surprised to learn that a man had been hired as the school’s head teacher, being paid twice her salary to run the school that she had set up and made successful. Outraged at this news, she quit her teaching position. “I may sometimes be willing to teach for nothing, but if paid at all, I shall never do a man’s work for less than a man’s pay,” she said.

In 1861, the Civil War began; Barton began collecting supplies and got passes from the government to send her supplies and services to the front line and field hospitals. And then she became known as the “Angel of the Battlefield”.

In 1869, Barton took a trip to Switzerland where she learned about the International Red Cross. Later, Barton set up the American Red Cross. Under Barton’s leadership, the American Red Cross helped thousands of people in need.

During her lifetime, Barton gave her life and effort to the service and the care of others as a teacher, a Civil War nurse, and founder of the American Red Cross.

8 . Do Dolphins Have a Language?

We know that dolphins make unique sounds, but is that a language? If you’re interested in it, you are welcome to the activity recommended by Denise Herzing!

About Denise Herzing

Denise Herzing of Florida Atlantic University (FAU) is the organiser and research director of the Wild Dolphin Project, which has a goal of understanding dolphins’ social system, behaviour, and communication. For over thirty years, she has spent each summer watching Atlantic dolphins carefully in the Bahamas.

Activity Guide:

Purpose:

Dolphins use sound to communicate, but they can’t make sounds in the way we humans make. Out of the water dolphins can make different sounds by changing the shape of their blowhole (呼吸孔), which is similar to changing the shape of our own mouths. Underwater, though, they use a totally different system, and they make sounds without letting any air out. You can learn more about how that works here. In this activity we’re going to try to talk like a dolphin.

Materials:

Nothing! But find a partner, maybe a brother or sister or a parent — or if you have one, a dog or cat. After all, this activity is about communication between humans and animals.

How To Do It:

Take a deep breath, hold your nose to keep it shut, and try to communicate with your partner. If your partner is a pet, try saying its name or asking it to “come here”.

When you’re done, think about what made it hard, what solutions you found, and think why dolphins may have developed to communicate in this way.

Then listen to sounds from all kinds of sea animals and compare your dolphin sound to theirs.

9 . What does Beijing’s Palace Museum look like at night? Many people don’t know the answer to this question, as it closes at around 4:30 p.m in winter and 5:00 p.m in summer. However, to celebrate the Lantern Festival, Beijing’s Palace Museum opened its door to the public after dark——for two nights only. That’s a first in 94 years!

Although people could get free tickets on the museum’s website, it was difficult to get a ticket. The website even stopped working for a while because too many people visited it at the same time. Zhang Zhifu, a 77-year-old woman, received a ticket from the museum as a gift.   “I grew up in Beijing and I visited the Palace Museum every year, but I never got to see it at night, It is truly an honor.” She said.

In the past celebrating the Lantern Festival was a tradition for the imperial(皇帝的) family. “We want to pass the tradition on and give people more festival experience.” Said Shan Jixiong, the head of the Palace Museum. On the night of February 19th, 2019, about 3,000 visitors spent the Lantern Festival in the Palace Museum.