Bats search for food in the dark using echolocation (回声定位), but that doesn’t mean that they can’t see, though they’re often wrongly thought to be blind. Research shows that many bats actually have good eyesight (视力) and use it to help them find food.

There are over 1,300 different kinds of bats in the world. Some feed on flowers, others on insects, and a few even feed on blood. Different kinds have developed different visual (视觉的) abilities. Many bats use both eyesight and echolocation when looking for food. Fruit bats, for example, don’t echolocate at all and actually have better eyesight than most humans. Even bats that eat insects prefer using eyesight when possible. Far from being useless, bats’ eyes are used to the dark environment to better help them look for small animals. Also, the eyes are improved by their great hearing power.

In a word, bats are not blind. They have different degrees of visual abilities and use them along echolocation to look for food. So now, being “as blind as a bat” doesn’t sound so bad, does it?

3 . Humans and dogs have been living and working together for thousands of years. Because of their protective (保护的) and playful nature, people often get dogs as pets for children. Today, because of their natural curiosity and excellent sense of smell, many dogs are being trained to help with different kinds of search and rescue (救援) jobs, for example, when a skier is lost in a snowy wilderness area or a child disappears in a forest.

The first known use of dogs to help rescue people took place in the Great St. Bernard Pass, a route (路线) in the mountains between Switzerland and Italy. There, hikers often became lost during bad winter weather. For many centuries, a group of monks (僧人) ran a small hotel there where travelers could spend the night. In the 17^th century, the monks began taking dogs with them when they went out to rescue lost travelers. They knew the dogs could use their sense of smell to find people, but they soon discovered that the animals also had an excellent sense of direction, even when it was impossible to see anything through the heavy snow. Using dogs for search and rescue jobs became common during the First World War.

★ They have to go through strict training. The training can last up to two years, and trainers look for four qualities in the animals they choose: being able to communicate well with humans; focusing on one thing for a long time; enjoying playing games since the training includes doing the same thing over and over again; finally, it must follow orders all times or it might fight back. Dogs with these have become a valuable part of many life-saving teams around the world.

6 . Every spring, thousands of fish swim through Utrecht, a city in the Netherlands, to find a place to lay their eggs. In this process, they help eat insects and keep the waterways clean. However, there is one problem. They have to wait at the Weerdsluis lock (水闸), which is usually closed at this time of year.

After knowing that, local ecologist Mark van Heukelum decided to help the fish. He learned that the lock keeper didn’t know when there were fish waiting at the lock. Mark set up an underwater camera at the lock and connected it to a computer and an online doorbell. When someone sees fish waiting to pass, they press the doorbell and the lock keeper will open the lock to let the fish through.

But Mark couldn’t keep watching the doorbell day and night. He reached out to the public to see how many people would like to lend a hand. He was surprised. In its first spring in 2021, the Fish Doorbell was rung more than 100,000 times by people all around the world.

This spring, people’s interest didn’t seem to wane. On the website, the number of visitors was always over 100 and could go as high as 500, depending on the time of day. Politely holding a door open for the friends of humans in the water is a feel-good act of kindness.

Some people are thinking of ways to automate (使自动化) the doorbell. But Mark thinks takes a different view. “I hope when spring comes, people will be excited to ring the doorbell again.”

7 .    请仔细观察下面图片并发挥想象，用英语写出一篇涵盖每张图片内容且结局完整的故事。故事的开头已经给出。

Millie is a middle school student who loves playing with little animals. One day, when she was on her way to school, __________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________