Scientists like to study weather. One of the main reasons is that many places in our world are becoming hotter and the weather is becoming stranger. Unluckily, we may not be able to stop these variations. Why? The weather on our planet is so difficult to understand!

Here is an example of our world’s strange weather: one Roman man wrote about frogs（青蛙）raining from the skies almost 2,000 years ago. Can this be true? Yes, it can! And, not only can frogs “rain”, but also fish and other small animals. This can sometimes happen when a storm（暴风雨）brings very big winds which blow over the tops of oceans （海洋）or lakes. Small frogs and fish are not very heavy, so the winds take them to the skies and then they come back down with the rain.

The frog rain is not new in many places. In 2005, people in the European country of Serbia walked outside their homes after a storm, and couldn’t believe their eyes. Hundreds of frogs were trying to jump back to water. The Huffington Post, an online news service, tells of many more places in the world where this has happened.

If you are interested to see what “raining frogs” looks like, you can go to watch the 1999 movie Magnolia. It shows a large number of frogs falling down in a small town in the United States.

What time of day can you think most quickly? Are you a morning person? Or does it take you a few hours to get your brain(脑)going? A lot of recent research suggests that we should pay attention to our body clock. It can tell us what time of day we can perform best at.

Many people work best later in the morning. This is because the body’s temperature rise quickly.

But everyone’s body clock is different and some are special. Morning people will get up early and work better early in the day. Evening people will work later but work better towards the end of the day.

Research shows that we’re better at some activities at certain times of the day. Physical performance(体能)is at its best between 3 pm and 6 pm, so it’s better to exercise later in the day.

Between noon and 4 pm, people begin to pay less attention. This is because we think less quickly after a big meal. Research also shows we become sleepy around 2 pm. This is why people in Spain take a short sleep in early afternoon.

Finally, it is best to eat when we’re active. This allows our body to burn calories(卡路里) better and stops our blood sugar levels（血糖）from getting too high.

Your mom tells you to put on your hat and gloves. But as the cold winter season gets closer, it’s so cold that even mom’s advice does not work.

That means it’s time to put on your qiuku! This is a kind of “thermal underwear (保暖内衣)” or long underpants that keep people warm in the coldest months of the year.

In Western countries, qiuku is usually known as long johns, but they aren’t popular. Long johns in the US are usually two pieces, a long-sleeved (长袖的) shirt and long pants, worn under other clothing or sometimes even used as pajamas (睡衣).

Long johns first appeared in England during the 17th century. We call them long johns because the US boxer John L. Sullivan wore them while he boxed. But this is not a historical fact.

In the US, it gets quite cold and snowy in many places. And while parents often push kids to wear more clothes and long underwear, it’s very special when young people actually (实际上) put them on.

Part of the reason might be because it’s not very fashionable (时尚的) and another reason might be because people don’t spend much time outside during the cold months. So they just deal with the freezing (冰冻的) temperatures when they have to leave the warm building. But in their parents’ eyes, staying warm is more important than looking nice.