While beach vacations may be a great way to take your mind off work，lakes surrounded by mountains make for an even grander experience．If you are looking for some peace on your vacation，we have some recommendations for you in the Caucasus(高加索)．

Lake Sevan

    Lake Sevan is situated in the central part of Armenia，in the Gegharkunik province．It is the largest lake in Armenia，located 6,200ft above sea level．Along the lake shore，there are various accommodations such as resorts and hotels with plenty of activities to partake in such as windsurfing，swimming and sunbathing．While there，do not forget to visit one of the famous cultural monuments，the Sevanavank Monastery，and it offers a great view of the lake as well．

Lake Paravani

    Lake Paravani，located at 6,801ft above sea level，is in the south of Georgia，near the Javakheti plateau．At this level，altitude sickness can occur and it is a good idea to be prepared to adapt to it properly，or bring medication for altitude sickness．Being a volcanic lake makes for a more interesting experience．The lake is best known for fishing．Do not come home during the winter months when the lake freezes．

Lake Cildir

    Lake Cildir is located in the Ardahan province，East Turkey，near the borders of Georgia and Armenia．It is the second largest freshwater lake of Eastern Turkey，and many tourists are not aware of this beautiful attraction．Lake Cildir is surrounded by mountains of the Caucasus．The lake freezes during late November．If the winter is not extremely cold，you can try some lake activities like ice skating and ice fishing．

Lake Van

    Lake Van is the must visit of all lakes in this list．The largest lake in Turkey，Lake Van is located on the eastern shore of Turkey and is also the most accessible lake here．It's situated at 5，380ft above sea level，and unique to lakes around the world，the water is high in salt content．

    Top 4 Amusement Parks in the World

    It's summertime! That means parents have extra time to spend with their children, and what better way to engage in classic fun with family and friends than to visit an amusement park? Take a look at these fun choices — perfect summer trip ideas to fit every budget(预算).

    Cedar Point

    Tickets: $280 for adults, $120 for children

    Praising itself as the roller coaster capital of the world, Cedar Point's 18 coasters will ensure you're riding all day. Reader Alicia Goettemoeller describes the park as a “paradise for excited thrillers” while reader Nick Schuyler says it is “built for grown-up kids.”

    Knoebels

    Tickets: $120 for adults, $10 for children

    This old-fashioned amusement park is a must for your old memory games as well as money saving - admittance and parking are free of charge. Reader Tracy Ginsburg Maier says “a family of 4 can enjoy special offer to eat, swim and ride all day for $100” at Knoebels.

    Kings Island

    Tickets: $340 for adults, $160 for children

    Kings Island is one of the most visited theme parks in the US, with more than 3 million visitors per year. The park is especially known for its family-friendly attractions, such as Snoopy Island. Tickets to the main park also include admission to the nearby water park, Boomerang Bay.

    Dells Water Parks

    Tickets: $140 for adults, $80 for children

    Wisconsin Dells is a water park with dozens of indoor and outdoor water parks to spread around in. One of them, Noah's Ark, is the largest outdoor water park in the US. Many are open year-round and no charge for children under five.

    Windbreaks are barriers (屏障) formed by trees and other plants. Farmers plant these barriers around their fields, which help prevent the loss of soil, stop the wind from blowing soil away. They also keep the wind from damaging or destroying crops. Besides, extra trees and plants can be cut down and used or sold for wood.

    Windbreaks can be highly valuable for protecting grain crops. For example, in parts of West Africa grain harvests were as much as twenty percent higher in fields protected by windbreaks compared to fields without them.

    But here is something interesting about windbreaks. They seem to work best when they allow some wind to pass through the barrier of trees or plants around a field. If not, then the movement of air close to the ground will lift the soil. Then the soil will be blown away. For this reason, a windbreak works best if it contains only 60 to 80 percent of the trees and plants that would be needed to make a solid line. An easy rule to remember is that windbreaks can protect areas up to 10 times the height of the tallest trees in the windbreak.

    There should be at least two lines in each windbreak. One line should be large trees. The second line, right next to it, can be shorter trees or other plants with leaves. Locally grown trees and plants are considered the best choices for windbreaks. Trees reduce the damaging effects of wind and rain. Their roots help protect soil from being washed away. And trees can provide animals outdoors with shade from the sun.

A Teenage Inventor

    The world could be one step closer to quick and inexpensive Ebola detection thanks to a teenager from Connecticut.

    Olivia Hallisey, a junior at Greenwich High School, was awarded $50,000 in the Google Science Fair for her new method that detects Ebola, a virus that causes bleeding from different parts of the body and usually causes death. Olivia's method is to ask patients to put their saliva (唾液) onto a testing card. The card changes color if the person is catching Ebloa. Present Ebloa tests take up to 12 hours and cost $1,000. Olivia's method, however, can be done just in 30 minutes for about $25. Besides, the sample (样本) doesn't have to be put in a refrigerator thanks to the silk material Olivia uses to produce the testing cards.

    Olivia was inspired to deal with this global problem after watching the news that more than 10,000 people died from Ebola in West Africa. She was particularly worried about the fact that, while the acts of involvement can improve survival rates, present detection methods are costly, time-consuming and require complex tools. Olivia got help from her science research teacher. She drew out directions from past research, and figured out detection systems that have proven to work with other diseases, including Lyme disease and yellow fever.

    "What affects one country affects everyone," Olivia told CNBC. "We have to work together to find answers to the huge challenges which cause harm to the global health." The Connecticut's teen, who hopes to become a doctor one day, was named the Google Science Fair winner in the competition of 20 competitors from across the globe. The fair is open to young people between the ages of 13 and 18 in most countries.

    Olivia hopes her success will inspire other girls interested in science and computers. "I would just encourage girls to try it in the beginning, and remind them that they don't have to feel naturally drawn or feel like they have a special talent for maths or science," she told CNBC, "but just really look at something they are interested in and then think how to improve something or make it more enjoyable or relate it to their interests."

    Hacking isn't just for computers and smart phones. According to a study, scientists have found a way to hack a plant's genes in order to make it use sunlight more quickly. Someday, the results could increase the number of food produced around the world.

    Scientists used tobacco plants in the study because it is easy to change the plants^' genes. Hacked plants are larger than normal plants.

    Photosynthesis is the word used to describe how plants use sunlight, water and carbon dioxide to make their own food. Scientists say this is a very slow process. Plants use less than 1 percent of the energy. But by hacking a plant's genes, the scientists were able to increase the amount of leaf growth on plants between 14 and 20 percent. Scientists hacked the plant's protective system. Normally, this system starts when a plant gets too much sunlight. When the plant senses the light, it creates more leaves. When the plant is in shade, the protective system is turned off. But the process is slow.

    The new study sped up the process by changing the plant's genes, the protective system turned on and off more quickly than normal. As a result, leaf growth on the plants scientists used in the study increased. Leaf growth on two plants increased by 20 percent, while leaf growth on a third plant increased by 14 percent. Scientists conducted the study on tobacco plants. But they think the genetic changes would produce the same results in corn and rice.

    Agriculture professor Tala Awanda said the study makes sense, but cautioned the yield（产量）might not be quite so high for conventional food crops. Still, she added in an email, "this study remains a breakthrough,"

Amsterdam Destination Guide

    Amsterdam is one of the most popular travel destinations in the world, famous for its beautiful canals, top art museums, cycling culture and so on. It is the capital and most populous city in the Netherlands and often referred to as the “Venice of the North” because of its expansive system of bridges and canals. Here are some of the key points to remember as you plan your trip to Amsterdam.

    Must-See Attractions

    Most visitors begin their Amsterdam adventure in the Old Centre, which is full of traditional architecture, shopping centers, and coffee shops. You'll also want to check out Amsterdam's Museum Quarter in the South District, which is great for shopping at the Albert Cuyp Market and having a picnic in the Vondel park. The top museums to visit there are the Rijks musuem, the Ann Frank House, and the Van Gogh Museum.

    If You Have Time

    There are several other unique districts in Amsterdam, and you should try to explore as many of them as time allows. The Canal Ring is a UNESCO World Heritage Site that was originally built to attract wealthy home owners and is a center for celebrity spotting and nightlife today. The Plantage area has most of the city's museums, including the Jewish Historical Museum, the Scheepvaart Museum, and the botanical gardens.

    Money Saving Tips

    Unless you really want to see the tulips (郁金香) blooming, avoid booking between mid-March and mid-May. This is when hotel and flight prices rise.

    Look for accommodations in Amsterdam's South District, where rates are generally cheaper than in the city center.

    Buy train tickets at the machine instead of the counter to save a bit of money.

    Instead of hiring a tour guide, hop on a canal boat. They're inexpensive and will give you a special point of view of the city.

    Check out our homepage to view price comparisons for flights, hotels, and rental cars before you book.