America's Best National Parks

Pacific: Yosemite National Park, California

Closest city: Oakland, Calif. (3.5-hour drive)

    This Golden State treasure has thick forests and rock formations like the Half Dome—a naturalist's dream in winter, spring, summer or fall. “Anytime of year, it's such an important park,” says Patricia Schultz, author of 1000 Places to See Before you Die. She recommends taking a tour with a naturalist guide to learn about the reintroduction of wolves into the park.

Pacific: Denali National Park, Alaska

Closest city: Fairbanks, Alaska (two-hour drive)

    Denali National Park includes the towering Mt. McKinley. At 20,320 feet, it's America's tallest peak. “But the park's real glory is the wildlife viewing in a setting that is vast, terrific and pristine(原始的),” says Schultz.

West: Grand Teton National Park, Wyoming.

Closest city: Jackson, Wyo. (45-minute drive)

    Home to ski paradise Jackson Hole, the Grand Tetons offer a charming Wild West view in any season. Schultz especially likes the park for its cross-country skiing and wildlife sighting opportunities.

East: Acadia National Park, Maine

Closest city: Bangor, Maine (45-minute drive)

    A former haunt(消磨时光的去处) of an older generation of America's wealthiest, this stretch of coastline once played host to Rockefeller, Astor and Vanderbilt. Easy hiking trails(小道) lead through forests dotted with small lakes.

Ways to sleep smarter

    Studies show that poor sleep influences people to make good decisions, concentrate on tasks or even manage a friendly mood(情绪) at work. {#blank#}1{#/blank#} Today we've got our top favorite sleep tips and facts.

Set a regular bedtime

    {#blank#}2{#/blank#}Choose a time when you normally feel tired. Try not to break this routine(惯例) on weekends when you will probably stay up late. If you want to change your bedtime, make the change gradually, such as 15 minutes earlier or later each day.

Eat the right food

    Some foods are more helpful to a better night's sleep than others.{#blank#}3{#/blank#} Others like bananas, potatoes, and whole-wheat bread are also helpful.

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    Exercising provides lots of good health benefits(好处). A good night's sleep is one of them. But make sure you exercise in the morning or afternoon. The National Sleep Foundation reports that exercise in the morning or afternoon can help deepen sleep. However, those who worked out in the evening hours saw little or no improvement in their sleep.

Reduce(减少) screen time before bed

    {#blank#}5{#/blank#} A recent study shows that people who use electronic media(媒体) just before bedtime report lower-quality sleep even when they get as much sleep as those who don't.

A. Avoid the alarm clock.

B. Exercise to improve sleep.

C. Try to solve problems in your sleep.

D. Go to bed at the same time every night.

E. There are many ways to increase the quality of your sleep.

F. Everybody knows that warm milk helps people sleep better.

G. Stop watching TV just before bedtime and you'll sleep better.

    Can exercise during childhood protect you against memory loss many decades later? Exercise early in life seems to have lifelong benefits for the brain, in rats at least.

    “This is an animal study, but it shows that physical activity at a young age is very important—not just for physical development, but for the whole lifelong track of cognitive (认知的) development during ageing,” says Martin Wojtowicz of the University of Toronto, Canada. “In humans, it may delay the appearance of Alzheimer's symptoms (阿兹海默氏症), possibly to the point of preventing them.”

    Wojtowicz's team divided 80 young male rats into two equal groups, and placed running wheels in the cages of one group for a period of six weeks. Around four months later-when the rats had reached middle age-the team taught all the rats to connect an electric shock with being in a specific box. When placed in the box, they froze with fear.

    Two weeks later, the team tested the rats in three situations: exactly the same box in the same room, the same box with the room arranged differently, and a completely different box in a different room.

    The rats without access to a running wheel when they were young now froze the same percentage of times in each of these situations, suggesting they couldn't remember which one was dangerous. But those that had been able to run in their youth froze 40 to 50 percent less in both changed box settings.

    “The results suggest the amount of physical activity when we're young, at least for rats, has influence on brain and cognitive health-in the form of better memories-when we're older,” says Arthur Kramer of Northeastern University in Boston, who has found that, in humans, exercise promotes the growth of new brain cells.

    Sharpshooters refer to those who are skilled at firing a gun and accurately hitting what they are aiming at. However, some fish are also called amazing sharpshooters. People wonder how they hit their targets without using tools? By spitting! The fish shoot so accurately that they rarely miss their target.

    These amazing fish are archerfish (印度射水鱼).There are several different types of archerfish living in Southeast Asia. They spit at their dinner to catch it. To catch dinner, a fish first sets itself in a certain place, for example just below the surface of the water. It puts the tip of its mouth so it barely breaks through the water. Then, the fish waits for an unsuspecting insect to land on a leaf or branch hanging over the water.

    When an unsuspecting, or unknowing insect lands, the fish attacks. The fish squeezes its gill (腮)covers very rapidly, which forces water into the fish's mouth. In the roof of its mouth the fish has a groove (槽）. The fish forms the small groove and its tongue into a narrow tube by pressing its tongue up against its groove. The water forced into the fish's mouth is forcefully pushed out of the fish's mouth through the tube. Archerfish have been known to send a stream up to 5 meters (16 feet). However, archerfish can only shoot insects up to 1-2 meters (3-6 feet) away due to their limited accuracy.

    When the unsuspecting insect is hit with a sudden stream of water, it is knocked into or falls into the water. Once in the water, the insect becomes dinner. Archerfish learn how to spit when they are young. They get more accurate with practice. Adult archerfish rarely miss.

    Within a meter, archerfish will often spring out of the water and grab an insect in their mouths.

    In beautiful rural Montana lies the town of Livingston. Around half the students in the Livingston School District qualify for free or reduced-price lunches, according to local educator Rachael Jones, known as "Farmer Jones". She is the director of the Livingston Farm to School program, which uses the district's two greenhouses and four gardens to grow food that supplements school meals while offering kids hands-on lessons. Jones said, "In many places around the country, if you can't pay for your school meal, you don't eat. Well, here, we don't turn anyone away."

    The town's school district and community members started the program eight years ago. It's part of the National Farm to School Network, which aims to increase access to local food and nutrition education across the country. Jones, who attended public school in Livingston as a kid, has headed up the local program since 2014. Farm to School enriches curriculums in all of the schools through garden lessons, cafeteria and kitchen lessons, and classroom lessons.

    Research has shown that healthy school meals can enhance academic performance, including improved test scores. Though the Farm to School program is not aimed solely at lower-income students, Jones said, "Such kids are more likely to eat lunch provided by the school. Eventually she wants to get healthy, affordable meals on the plate of every child in Livingston.

    It is important for kids to understand where their food comes from. That's a life changing experience for them. Jones said," When I grew up a big force in my life was my grandma Ethel. She taught me from a really early age the value of growing my own food. I worked in her gardens with her and somehow, through all of those experiences —eating her tomatoes and canning pickles with her —it really built up my trust and knowledge in food systems. I'm so thankful for her!"