Do you suppose Darwin, one of the greatest scientists of all time, really did fools’ experiments? Or did he do experiments that were so simple and basic that other people just thought they were foolish?

Sometimes, people think they already know the answer to a question or the solution (解决办法) to a problem. Sometimes, they really do know an answer or a solution, but without thinking they are important.

Charles Darwin didn’t settle for (满足于) just thinking he knew something. And, he believed all things could be important however simple they seemed to be.

Suppose you drop sheets of paper that are of exactly the same size and shape. If you drop them at the same time in the same place, they will fall in the same way. Now make one of the sheets of paper into a tight (紧的) little ball and let it drop along with the other sheets. What happens? You have done an experiment that is so simple that you might think it couldn’t be worth anything.

But this simple experiment is important. It explains part of our present-day understandings of physics and ideas that were worked out long ago by Galileo and Newton. And these understandings set aside some of ancient Greek physics.

A scientist sometimes stops to look at very simple things and to think very hard about them. Even the simplest idea, which we might think is foolish, can shake the foundations of science.

One night, Pilar was in a deep sleep when she was woken by her cat Inti. Inti was meowing wildly outside Pilar's bedroom and throwing himself against the closed bedroom door.When Pilar opened her eyes, she saw that her bedroom was filled with smoke. As she escaped her house with Inti in her arms, she saw that a fire was burning in her kitchen. Pilar could easily have lost her life,but Inti would not let that happen. Even though Inti could have escaped the house through a cat door, he wouldn't leave Pilar.

As amazing as this story is, it is not as uncommon as you may think. Take the example of Charlotte Lee and her horse,Thunder. One summer night, the whole family was asleep with the windows open. It was normally very quiet where they lived. Suddenly, there was a loud noise. Charlotte woke up from her sweet dream, and the noise continued. Then she heard a horse running fast towards the house. The next thing she saw was Thunder standing outside her window, neighing and shaking his head. She knew something was wrong. Charlotte quickly got everyone out of the house before the earthquake hit. Thunder has saved her life.

There are also stories of wild animals coming to the rescue of humans. One animal known to be a friend of humans is the dolphin. Once, Todd Endris was surfing with his friends when he was attacked by a 13-foot (4-metre) shark. In the middle of the attack, a group of dolphins came to his rescue by forming a protective ring around Endris until he could get safely to the shore. Without the help of the dolphins, there is little chance that Todd could have escaped.

No one is sure why animals have so often come to our rescue. However, it is clear that humans and animals enjoy a close relationship. It is important that we care for them as much as we can.

Cities are diverse ecosystems. Some wild animals become regular visitors to our cities, such as coy-otes (丛林狼) in Los Angeles or boars (野猪) in Berlin. 【小题1】As our cities spread, we need to think about what it is like for other species to have human neighbors.

【小题2】They do not always provide suitable habitats for wildlife. For example, most city parks are kept neat and tidy so that humans will find them beautiful. But when we cut grass or plant flowers, we destroy natural habitats.

Our actions sometimes help other species. When a bridge in Austin, Texas was repaired, engineers added small gaps running along the length of its bottom. This made a good home for bats, and soon the bridge was the home of thousands of bats. At first, people were afraid of the bats and tried to get rid of them. 【小题3】 The bats are a tourist attraction, and they eat lots of bugs every night.

There are also structures built with the aim of bringing wildlife into the city. The Beijing Olympic Forest Park is a good example. The park used native plants and created open, natural spaces for wildlife. The result is a zone in Beijing with over 160 species of birds. 【小题4】Instead of being kept in cages, wildlife can move about freely. Sometimes, the visitors can encounter a gaggle of geese walking on the bank or swimming in the water leisurely.

While cities pose challenges for wildlife, they are finding ways to adapt and thrive in urban environments. As humans, it is important to take measures to prevent conflicts and appreciate the presence of them. 【小题5】 And our own future will be endangered.