1 . If you’re a primate (灵长目动物) or a koala, you have something different compared to other animals: fingerprints. Now, a new study explains how our fingerprints help us keep a grip on the surfaces that we come into contact with — and it’s all to do with regulating moisture (水分). Researchers decided to investigate this using advanced laser imaging technology and discovered a finely tuned system controlling how wet or dry our fingertips are. That means our fingers are able to react to the various types of surfaces they’re pushed up against, making the grip as strong as possible with everything from a phone to an umbrella,and preventing “catastrophic slip”where we lose hold of objects.
Close-up (特写镜头) laser imaging of volunteers touching glass showed that when fingertips make contact with hard, impermeable surfaces, extra moisture is released to increase friction and grip. However, the sweat pores are eventually blocked off to avoid contacts that are too slippery.
This sweat-pore-blocking technique is combined with an accelerated evaporation process, controlled by the ridges (隆起) of the fingerprint, that comes into play when excessive moisture needs to be removed-again,with the ultimate aim of keeping a strong contact between finger and object.
Working together, the two biological mechanisms are able to adapt to surfaces whether our fingers are originally wet or dry: They provide the keratin(角质) skin layer with just the right amount of hydration (水合作用). That gives us skills that smooth-handed and smooth-footed animals don’t have.
Besides telling us more about the human body, the research is likely to help product designers who need to design a gadget (小装置) that humans need to interact with, such as a smartphone.
Further down the line, the findings might even benefit the development of grip on prosthetic (假体的) limbs and robotic equipment, as well as devices that are used to explore virtual reality environment (where the sensation of touch might need to be simulated).
1. Why does the author refer to a koala?| A．To explain different species are often in conflict. |
| B．To indicate people know little about its fingerprints. |
| C．To introduce the newly discovered function of fingerprints. |
| D．To highlight its reliance on fingerprints. |
| A．Transparent. | B．Waterproof. | C．Uneven. | D．Invisible. |
| A．The sweat pores are closed for a while when we hold things. |
| B．The time when the sweat pores work is controlled by the ridges of the fingerprint. |
| C．The ridges of the fingerprint are insensitive to excessive moisture. |
| D．Prosthetic limbs and robotic equipment benefit most from the findings. |
| A．No Fingerprints, No Grip |
| B．Irreplaceable Benefits of Fingerprints |
| C．Two Biological Mechanisms Matter for a Grip |
| D．Fingerprints Give a Better Grip |
2 . Be at your best!
What does your brain need to work well? Here are some things it needs.
Good food
Experts say that breakfast is much more important than any other meal.
A regular supply of energy
Your brain needs a regular supply of energy, so you need to eat carbohydrates (碳水化合物). They’re found in bread, rice, pasta and beans.
A continuous supply of oxygen (氧气)
Your brain needs oxygen, which it gets from exercise.
Water
Your brain needs several hours’ sleep, so it can ‘update’ itself, just like a computer. Experts say that when you study for a test or an exam, you should get some sleep as quickly as possible after you’ve finished studying. This helps you to remember what you’ve learned.
| A．A short break |
| B．A good night’s sleep |
| C．It works best in the morning. |
| D．Exercise improves your memory too. |
| E．Water is much better than sweet drinks. |
| F．Your brain works better when you have eaten. |
| G．Chocolate, biscuits and sweets are not good for your brain. |
