Have you ever bought Genki Forest（元气森林）sparkling water because it’s advertised as “sugar-free? It’s popular among students. The company recently apologized for a misleading advertisement.

The company said the drinks are “sucrose-free”（零蔗糖）, but this is not the same as “sugar-free”. Now the company has changed the words “sugar-free” to “low sugar” on the bottles.

In fact, there are many kinds of sugar. Sucrose is just one of them. Other kinds of sugar, such as fructose（果糖）（糖醇）, are still in Genki Forest drinks. These types of sugar are used as sweetener（甜味剂）. They offer little energy, but also avoid taking in too much sugar.

However, studies find that the sweeteners might make people eat more. When you eat sweet-tasting things, it sends your brain a “sweet signal”! Then your brain tells your body to prepare itself to take in energy. But since the diet soft drink has little energy, you will feel hungry and start getting energy by eating more food.

According to China Daily, drinking too many diet drinks might lead to obesity（肥胖）and type 2 diabetes（糖尿病）. It’s time for you to think twice about the diet drink trend.

People have different ways of greeting each other. They might shake hands (握手), kiss or hug (拥抱). But do you ever wonder how dogs say hello?

If you are a dog lover, you already know the answer to this question. When you arrive home, your dog jumps up into your lap (大腿前部). It wags (摇摆) its tail, and sometimes gives you wet kisses.

Like humans, dogs have five senses (感觉): smell, touch, sight, hearing and taste. Humans use sight as the main sense for recognizing (认出) one another. But dogs have poor eyesight. They use smell to recognize others. A dog’s sense of smell is much better than a human’s. It is through its sense of smell that tells the differences between different people.

Dogs use smell to recognize other dogs, too. They tell the differences by the smell of pee (小便) and pooh (大便). When two dogs meet, they smell each other’s noses. Then they go side to side, and smell each other’s butts (屁股). By smelling its friend’s behind, a dog knows who it is with.

That is also why dogs smell everything they can on the road. By smelling grass, trees and signposts (路标), dogs know which other neighborhood dogs have been around.

For people who don’t like winter, animals that hibernate(冬眠) seem to have the right idea. Isn’t it great to bury your head under the covers(被子)until spring comes?

But is hibernation the same as sleeping?

Well, despite what you may have heard, animals that hibernate don’t “sleep” during the winter. Hibernation, in fact, is very different from what happens when you sleep. During hibernation, metabolism(新陈代谢) slows down greatly. When lemurs(狐猴) hibernate, for example, they reduce their heart rates. An active lemur’s heart beats 300 times a minute. _____ slows down, too. Hibernating lemurs can go ten minutes without taking a breath. Their brain activity becomes undetectable. During sleep, however, animals continue to breathe normally.

According to scientists, hibernation is a way for animals to save energy. It is often seen as winter behavior. However, animals that live in cold areas are not the only ones that hibernate. Some animals hibernate to beat the heat. For some, hibernation does not have to do with temperatures. Some animals hibernate when there is no food. Echidnas(针鼹), for example, will hibernate after fires. They won’t go back to normal activities until food grows back. Some animals hibernate to stay safe. Animals don’t smell(散发臭气) or move much when they hibernate. This makes it hard for other animals to find them and eat them.

There are many mammals(哺乳动物) that hibernate. Most of them are small. The average hibernator weighs less than 90 grams. Little animals usually lose heat quickly. It is hard for them to stay warm in winter, so they need to save more energy than larger animals do.

We human beings don’t need hibernation. So, don’t be lazy and lie in bed all day long during the coming winter holiday!