1．Some caterpillars' warning signals（信號(hào)）may have evolved（進(jìn)化）from walking.
   A team，writing in the journal Nature Communications，reported that the hair-like structures the living things use to make sounds evolved from legs.
   The team studied caterpillars which use these structures to communicate their ownership of leaves.This means the caterpillars are able to"tell"strangers to go away without risking injury in fighting."These are really interesting caterpillars，"said Dr.Jayne Yack from Carleton University in Ottawa，Canada，who led the research."They make signals using hair-like structures which are on their back ends."
   The caterpillars drag these structures across the leaf to make scraping（刺耳的）sounds when strangers enter the area of their leaves."When they make this signal，the strangers leave，"explained Dr.Yack."It's like saying'I'm here，get out of here-I already own this leaf '."
   The scientists looked at other species（物種）within the same group of caterpillars and created their"family tree".They used chemical markers（標(biāo)記物）to work out the relationship between the animals，showing which in the group were the more ancient species and which species evolved more recently."Those more ancient species actually don't have these sound-producing structures.They have legs that they use to walk towards strangers，"said Dr.Yack.These more ancient species，she explained，walk towards strangers and try to fight against them."They can kill each other in the fighting，"Dr.Yack added.She said that the evolution of the scraping show had allowed the caterpillars to solve their fighting without injury."So our idea is that these signals actually avoid harm to both sides-they solve fighting in a more' friendly' way."
   The study also provides a map of an evolutionary process that many other biologists are researching.

（1）What can we learn about caterpillars' warning structures from the text？
A．They have the same use as hair.
B．They are found in caterpillars' heads.
C．They are used to fight against strangers.
D．They may have evolved from caterpillars' legs.
（2）According to the text，Dr.Yack's team did NOT .
A．draw a family tree of caterpillars
B．create a map to show how caterpillars evolve
C．study species within the same group of caterpillars
D．make clear the relationship between different species of caterpillars
（3）What does the underlined word"They"in the fifth paragraph refer to？
A．The ancient species.
B．The chemical markers.
C．The sound-producing structures.
D．The more recently evolved species.
（4）What is the main idea of the text？
A．How caterpillars evolved.
B．How caterpillars warn strangers.
C．Communication between caterpillars.
D．Caterpillars' warning signals evolved from walking.

2．A joint research team recently have developed a new electronic skin that is similar to human skin in strength，durability（耐久性） and sensitivity.The skin or e-skin may play an important role in next-generation personalized medicine，soft robotics and artificial intelligence.
   "The ideal e-skin will mimic（模仿） the many natural functions of human skin，such as sensing temperature and touch，accurately and in real time，" says leading researcher Yichen Cai.However，making suitably flexible electronics that can perform such delicate tasks while also used repeatedly is challenging，and each material involved must be carefully engineered.
   Most e-skins are made by putting an active sensor on the surface that attaches to human skin.However，the connection between them is often too weak，which reduces the durability and sensitivity of the material；otherwise，if it is too strong，it won't be flexible enough，making it more likely to break the circuit.
   "The landscape of skin electronics keeps shifting at a remarkable pace，" says Cai. "The discovery of 2 D sensors has accelerated efforts to turn these quite thin but strong materials into functional，durable artificial skins."
   The new man-made skin built by the researchers could sense objects from 20 centimeters away.It could further make a quick response when touched in less than one tenth of a second. " It is a striking achievement for an e-skin to maintain toughness after repeated use，" said Shen， "which mimics the softness and rapid recovery of human skin."
   This type of e-skin could monitor a range of biological information，such as changes in blood pressure，which can be detected from movements of arms and legs.This data can then be shared and stored on the cloud via Wi-Fi.
   "One remaining problem to the widespread use of e-skins lies in mass production of high-resolution sensors，" adds group leader Vincent Tung "however，the latest technology offers new promise. "

（1）What's the feature of the new e-skin？
A．It can store information.
B．It's quite hard and tough.
C．It's flexible and sensitive.
D．It can replace human skin.
（2）Why does the author mention "most e-skins" in paragraph 3？
A．To stress the challenges of making e-skins.
B．To introduce the popularity of e-skins.
C．To show the process of making e-skins.
D．To compare the similarity between e-skins.
（3）What can the new e-skin do？
A．Adjust the blood pressure.
B．Recover the wounded skin.
C．Work as a remote controller.
D．Sense the outside temperature.
（4）What is the best title for the text？
A．A Breakthrough in Hi-tech
B．Man-made Skin，Improved
C．E-skin，A Promising Business
D．The Widespread Use of E-skin

3．

A.putting B.since C.danger D.as E.taking care of F.safety

Do animals feel love？Maybe.Maybe not.There're many signs of animal love in nature.Or，at least，there seem to be.They include mothers（1）their babies，or even family groups protecting one another from（2）.One scientist has made a discovery （發(fā)現(xiàn)）.The brains of some animals produce chemicals that are seen in human brains.In our brains，these chemicals are responsible （負(fù)責(zé)的） for the feeling of love.But some scientists doubt （懷疑） that animals really"feel" love.They say that we're just（3）our own feelings on the animals.We expect animals to love and protect their young babies（4）we do.But these scientists say animals do these things without any reasons.They say animals have no feelings.They only have natural behaviours（5）they were born.