Ants have the ability to find out cancerous cells in humans, a new study has discovered, suggesting they could be used for cancer diagnosis（诊断）in future.

Ants can discover the cancerous cells which are different from healthy cells. Thanks to their sense of smell, the study also added, ants could turn out to be better at locating（定位）cancerous cells in humans than dogs.

To improve their research, the scientists had tests with 36 ants, smelling cells under an experiment with a lower cost and efficient study. First, they exposed（暴露）the ants to the smell of a sample of cancerous human cells, then they were given sugar for a prize. In a second step, the scientists exposed the ants to two different smells. One was a new smell and the second was the smell of the cancerous cells. Finally, the ants followed the cancerous cells directly with the smell they had smelt in the first step. This test shows that ants can tell the differences between the cancerous cells and healthy cells with high talent, capability to learn quickly, points out CNRS in a news.

This isn’t the first time that scientists have used the animal sense of smell to find cancerous cells. For example, dogs’ noses are fit for medical diagnosis and used for the detection of cancer, which can offer the proper medical treatment, the scientists explained. However, training them to do so requires several months to a year.

The test could be used in various of other smell tasks, such as finding the differences among the drugs, explosives（炸药）, spoiled food, or other diseases.

If you put a buzzard in a pen six to eight feet square and open at the top, the bird will be a prisoner, though it can fly. The reason is that a buzzard always begins a flight from the ground with a run of ten to twelve feet. Without space to run, as its habit, it will not even try to fly, but remain a prisoner for life in its small prison with no top.

The bat that flies around at night cannot take off from the ground. If it is placed on the ground, all it can do is to walk slowly about helplessly and no doubt, painfully. If it reaches a higher place, it will be able to throw itself   into the air. Then it takes off immediately. But on flat(平的) ground, it will never fly.

A bee dropped into a cup will be there until it dies, unless it is taken out. It never sees the means of escape at the top, but keeps trying to find some way out through the sides near the bottom. It will look for a way where none exists(存在), until it completely destroys itself.

A．

B．

C．

D．

During the chase to catch a rabbit, a lion jumped into a small bush from where he came out not with the rabbit, but with a large thorn（刺）in his palm.

He shook his hand, and tried to pull out the thorn with his mouth, but all his efforts were in vain. Then he asked other animals for help. But they all feared the lion. So no animals came to help him.

At last the lion came up to a fox. He asked, “Can you pull out the thorn, please? I am suffering（遭受）very much with pain.”

The fox said, “I am not very expert in this task. But I have a little friend who is very expert in this work. I will surely ask him to help you. But I have a strong demand（要求）.”

“What is your demand?” asked the lion.

“It is not just food or money! You should allow me to give you five kicks on your back!” the fox said.

The lion was a little angry and he began to think for a moment, “I just want to remove the thorn. After his friend pulls out the thorn, I will eat up his little friend.” And then he let the fox kick him five times.

The fox called his little friend. There came a little porcupine（豪猪）. He pulled out the thorn with great ease. But the lion’s mind became filled with anger. What to say! How could he eat the porcupine with thousands of thorns?