“Don't get discouraged, Hallie,” Kathy said, comforting her with a hug. “It sounds as if you have a bit of a mystery to solve. Maybe you should do a little spying on Maya.”
Feeling better, Hallie put on her scuba gear（潜水服）again and waited. Maya, the dolphin, had been swimming playfully, but suddenly she threw herself to the back of the tank where the filter box（过滤箱）was located. She stuck her nose down behind the box and then swam away.
Hallie followed Maya. “What was she doing here?” she wondered. When she looked behind the box, her question was answered. She swam back and saw Maya was in front of Kathy with a comb in her mouth waiting for her treat.
“Maya! Where did you get that?” demanded Kathy, taking the comb and throwing her a fish.
“I know,” declared Hallie, handing Kathy a handful of items, “I followed her to the filter box and these are what I found.”
From the look on Kathy's face, Hallie knew everything was beginning to come to light.
“Do you remember the other day you said that Maya really liked her treats?” asked Kathy.“Well, I think this was more than a training exercise for Maya. Every time you found something in the tank, that meant one less fish for Maya. She couldn't bring all the items to me at once, so she found a hiding place for them. That way you came up empty-handed, but Maya would always get her treat.”
“Okay, Maya,” said Hallie facing the dolphin, “you win! The treats are all yours.”
Maya dived down, and then jumped out of the water, turning herself over in midair. Shaking their heads in disbelief, Hallie and Kathy reached for the fish. Maya deserved the treat.
Who could have imagined that a treadmill（跑步机）on wheels would one day become a thing?!? Lopifit is an unusual means of transportation that allows you to power an electric bicycle by walking on a treadmill.
Lopifit founder Bruin Bergmeester says it all started when he asked himself the question "How can I use a treadmill outdoors?" He finally came up with a new design, adding an electric motor, and the Lopifit was born. It's similar to an electric bicycle in that the motor only works when the rider puts power in as well. The Lopifit senses when you walk on the treadmill and uses the motor to turn a drive chain at the back of the treadmill, helping you reach a top speed of 17 miles per hour.
To use the Lopifit, simply turn on the battery（电池）and use your foot to slide the treadmill backwards and start the motor. Then get on and enjoy the ride! If you need speed, just walk on the treadmill, and if you want to coast（惯性滑行）, all you have to do is stay still and admire the view. To stop, you have two hand breaks.
The Lopifit first hit the streets in 2014 and, unsurprisingly, became a hit overnight. That was actually quite challenging for the company, because it started getting calls for orders, but it was nowhere near ready for mass production. The unique treadmill bicycle could be bought this year, and Lopifit is struggling to keep up with demand, although the price is up to $2,115.
Some people consider this means of transportation stupid and unnecessary, although there is a very loyal fan-base of so-called Lopifitters. They simply believe that if you're going to walk, you might as well do it the old-fashioned way.
But the Lopifit does have the special advantage of helping you "walk" really fast without much effort, or walking at cycling speed, if you will.
Like many Czechs (捷克人), Lukáš Berný, 38, enjoys going out to the pub with his friends for conversation and a few beers. "I don't drink every day," he says. "I think about three times a week. When I go out, I usually have five to six beers at a time, about the same as my friends." The beers are half-liters, or 500ml each.
If a half-liter of four-percent beer contains 16g of pure alcohol（酒精）, Berný and his friends are drinking 80 to 96 grams of pure alcohol on each outing. The Czech Republic's National Institute of Public Health, however, suggests that men take in fewer than 24g of pure alcohol per day; women, fewer than 16g.
Medical experts in over 40 countries around the world have agreed that drinking "too much" can cause harm. What they can't seem to agree upon is just how much is "too much." National safety levels are quite different, from a limit of 10g a day in the Netherlands to Denmark's 60g.
There are a number of reasons for this. Dr. Larry Altshuler, a medicine expert for the Cancer Treatment Centers in Tulsa, explains that while everything is based on research, "Every group, race, and gender responds to alcohol differently."
Also, researchers aren't using the same models or methods. He adds, "It can be like apples and oranges. How do you measure alcohol? Units, drinks, bottles or cans? What's the alcohol content（含量）? Is it light or heavy?" While a half-liter of four percent beer contains 16g of pure alcohol, a half-liter of five percent lager contains 20g.
Constance Scharff, a director of Addiction Research at Cliffside Malibu Treatment Center in California, says she believes the reason "is largely cultural." "But the evidence is clear that the more you drink, the more likely you are to develop alcohol-related health problems."
Did you know that money is not worth the paper it is printed on? Money is really just a symbol.
Long ago, people did not use money. They made or grew food, clothes, and other things they needed. Later, people started trading. They would trade what they made to someone else in order to get different foods and goods. To trade like this is to barter（物物交换）.
The barter system was a good system. Bakers could trade bread for wheat. Weavers could trade cloth for meat. Trading not just let people work at certain jobs.
But one problem with bartering was that not everyone agreed on prices. People had to work out a price each time they wanted to trade. Another problem was that the goods might be too heavy to carry. What if the cow farmer wanted to trade a cow for a horse with the horse farmer? They would have to carry their animals with them. What if the cow farmer wanted to trade a cow for a chicken? A cow is worth more than a chicken. The farmer should get “change.” But how can you make change from a cow?
People used to use all kinds of small things for money. They used shells, beads, feathers, seeds, and even salt. A group of people would decide the worth of a kind of shell. Other kinds of shells would be worth more or less. Then people had money that was worth a certain amount. It was easy to carry. It was easy to make change.
With time going by, we finally have the money that we use today.
A. This is where money comes in.
B. That means it stands for something else.
C. They made clothes from wool from their sheep.
D. Bartering did not have a way to make change, either.
E. It also gave people a way to buy things they needed.
F. With money, we don't have to travel with chickens, cows, or clay pots!
G. When people traded, they no longer had to make everything they needed.
I was sitting in the far back in a pizza house when I noticed the man, about thirty years old, carrying a pizza box. He sat down at the table to my right and then 1 his large dirty paper bag of clothing down on the floor. Obviously, this man was homeless and 2 a bath. He picked up the one small slice（薄片）of pizza and very slowly, very carefully, he began to eat, taking very little 3.
He finally finished his meal and did something that I would never 4. He turned the box on its corner and slid the few5bits into one corner. Then he 6 his index finger（食指）and tried to pick up the small bits.
Oh, how much it hurt me once again to see myself 7 I was thirty years ago. No food, no 8, and no clean clothes. Most of my past life had always been 9 to that of the young man and it all came back to me 10. The muscles in my neck began to tighten and my eyes began to burn and water up. I coughed a bit, trying to clear my 11 and get myself back together.
I got four large slices of pizza from the counter and sat them down on his table, saying, “I thought you 12 like to have a few slices.”
I did not stop at all but walked around behind him. As I passed him, I reached out and13him on the back, just one time, very softly with my hand. I hope that man knows that someone, someplace,14 him as a human being. And I am so 15 that I have never forgotten what it feels like to be down, out, dirty and hungry.
As a general rule, a band may start as a group of high-school students (share) the same interest in music. They may first practise their music in someone's house. And then the musicians may get the chance to give (perform) in pubs or clubs, for which they are paid cash. As time goes by, they gradually become known to the audience and some even make records!
The Monkees,, started in a different way. Of (it) four members, only one was good enough and the other three just pretended (sing) during the broadcasts. To be honest, it couldn't (call) a real band in the beginning. Anyhow, they succeeded and became so popular their fans formed clubs in order to get more familiar with them. (fortunate), the Monkees broke up about 1970. But they reunited in the mid-1980s and produced a new record in 1996, was to celebrate their former happy time.
活动事项包括：
1）分享一件为老师做过的暖心之事；
2）交流听后启发和感受；
3）赠送感谢卡。
注意：
1）词数80左右；
2）可适当增加细节，以使行文连贯；
3）开头和结尾已给出，不计入总词数。
Dear Jack,
Li Hua
