After touring the Mogao Grottoes（莫高窟）yesterday, we got up early this morning and headed out to the Mingsha Sand Dunes（沙丘）. We were very surprised when we saw them in front of us through the car window—they towered like mountains! Later, I read in my guidebook that some of the dunes are up to 250 meters in height. Amazing!

The name “Mingsha” means “singing sand,” because when the wind blows over the sand it sounds like a musical instrument being played. We didn’t hear anything that sounded like a musical instrument while we were there, however. What we did hear were the sounds of camels right inside the gates—there were hundreds of the camels   sitting there with their handlers. We decided to take a camel ride, and were soon glad we did, as it was the most wonderful experience of our lives.

The camels were calm and gentle（温和的）and the ride was actually quite comfortable. With their wide feet, they easily climbed up a sandy dune. At the top of the dune we saw mile upon mile of dunes stretch（绵延）out before us.

We stopped at one large dune with wooden steps on it, and we went sledding（滑雪橇）. It reminded me of when I was a kid sledding in the snow, but this was down a hill of warm sand. It was so fun that we tried it over and over again, until we were too tired to walk up the dune.

Finally, hot and tired, we decided to leave the dunes so that we could eat some cold spicy（香辣的）noodles. It was a perfect ending to a day we’ll never forget.

Have you ever dreamt about taking a great American travel adventure（冒险）? Most of us keep dreaming; others ________

Gregg Bleakney’s dream was to travel the Americas from top to bottom.

To pay for the journey, Gregg and Brooks worked and saved money for years. Once they were on the road, they often camped outdoors or stayed in rest houses. In many places along their journey, local people opened their homes to the two friends and gave them food.

During their tip, Gregg and Brooks cycled through deserts, rainforests, and mountains. Two years, twelve countries, and over 30,500 km later—At last, Gregg reached Ushuaia, Argentina, at the end of South America. （Near Guatemala（危地马拉）, Brooks had to return to the U.S. and Gregg continued without him.）

Gregg and Brooks kept a record of their adventures in an online blog. The trip taught both men a lot about travelling. Here is some of Gregg’s advice:

Travel light. The fewer things you have, the less you’ll worry about.

Be flexible. Don’t plan everything, then you’ll be more relaxed and happy.

Be polite. As one traveller told Gregg, “Always remember that nobody wants to fight, cheat, or rob a nice guy.”

About 150 years ago, the French writer Jules Verne showed what the future would be like in some of his books. He once said, “Anything one man can imagine, other men can make it come true.” Now, let’s take a look at the future in the eyes of some scientists.

Underwater (水下的) cities: As the world’s population increases, there’s less space for us to build houses. So, it’s believed that one day we could live underwater. By the year 2050, underwater cities could come out. These underwater buildings will be made of special material. It is possible for us to make the rooms bigger or smaller.

3­D printed (打印) foods: Many scientists believe that 3­D dishes will be the future of food. In the future, many kitchens may have a 3­D printer. And the best part is that 3­D printed foods can always have the same tastes as the recipes (配方).

Flying cars: Heavy traffic is a common problem today, and people have dreamed of flying cars. In the future, flying cars will be as common as bicycles. These flying cars will be something between a helicopter (直升机) and a plane. People will spend less time on traffic, probably cutting a 2­-hour taxi ride into a 15­-minute one.