请阅读下列短文, 从短文后各题所给的 A、B、C、D 四个选项中, 选出最佳选项

    People in the western state of California who are in the United States illegally can now request a driver's license. The law went into effect on January l. California is not the first American state with such a law, but it has the largest number of illegal immigrants. More than a million people began to request licenses shortly after the new state law went into effect. Among them was Christian Alvarado. Mr. Alvarado entered the United States from El Salvador eight years ago without permission from the U.S. government. Some call such people "illegal immigrants." Others call them "undocumented immigrants".

    Mr. Alvarado thinks it so exciting, for he has been waiting for the license for a long time. But some are worried that their personal information will be used to find them and deport them. Armando Botello is a spokesman for the California Department of Motor Vehicles, or DMV. He says people should not be afraid, for such information will not be shared.

    The new licenses are the same as licenses given to citizens except that they have the words "Federal Limits Apply". That means the license cannot be used to travel on an airplane or enter a federal building. Ana Garcia, working at the Central American Resource Center, says some illegal immigrants fear those words will be used to abuse them. Civil rights groups say the police and others will not.

    Dan Schnur, a political scientist at the University of Southern California, said that the main argument against the new law is that it rewards illegal behavior. But Professor Schnur argued that young, white Americans generally support immigration reform, including giving driver's licenses to illegal immigrants

    "It's simply because they grew up in a much more multicultural society than their parents or their grandparents did." Professor Schnur says he believes the changes in beliefs about illegal immigrants that have taken place in California will spread throughout the United States.

    Crown shyness (树冠羞避) is a mysterious natural phenomenon in which the crowns of some tree species do not touch each other, but get separated by a gap clearly seen from ground level. The effect usually occurs between trees of the same species, but has also been observed between trees of different species.

    There are many theories going around, most of which make sense, but no one has been able to prove without the shadow of a doubt why some trees avoid touching each other.

    In his 1955 book Growth Habits of the Eucalypts, Australian forester M. R. Jacobs writes that the growing tips of the trees are sensitive to abrasion (擦伤), which results in crown shyness phenomenon. This theory was also supported by Dr. Miguel Franco. Some experiments have shown that if trees displaying crown shyness are artificially prevented from swaying (摇摆)in the wind and touching each other, they gradually fill up the gaps between them.

    But while the above theory is arguably the most widespread, it's certainly not the only one. Some scientists have suggested that crown shyness is a mechanism to stop the spreading of leaf-eating insects. The gaps mean pests wouldn't be able to reach other trees, so they are the tree's natural defense method.

    One Malaysian scholar studied many trees, but found no traces of abrasions, despite their clear crown shyness. Instead, he suggests that the growing tips of the trees were sensitive to light levels and stopped growing when they got too close to other trees. Plants are able to sense how close they are to other plants and in order to get more light, they give off some chemical to stop other trees from growing too close.

    Whatever the reason, one thing is for sure, plants are more intelligent than people.

    Many science fiction stories tell about explorers arriving in a new world. The explorers then use some kind of high-tech device to test for breathable air or signs of life. But here on Earth, science fiction is becoming reality through a new sampling technology called environmental DNA, or eDNA for short. Scientists can use it to identify rare species or estimate fish populations with just a little air or water.

    Environmental DNA can be used in two ways. One is to identify the creatures that live in a certain place. The other is to confirm the presence or lack of a specific creature.

    Caren Goldberg is one of the first biologists to take the technology from the testing stage to actually using it. She sees eDNA as a way to get answers more efficiently and with less destruction compared to traditional survey techniques. Until recently, scientists depended on snorkeling ( 潜水), netting or using an electric current to temporarily catch fish.

    This newer way to identify what lives in the environment is becoming popular around the world. Animal experts in Vietnam are using the eDNA to find the last, wild Yangtze giant softshell turtles. One researcher on the Caribbean island of Trinidad is using the sampling technology to find endangered golden treefrogs. In Madagascar, it is being used to identify amphibian(两栖动物)diseases.

    Ms Goldberg has used eDNA testing to confirm the local extinction (灭绝) of a leopard frog in the American state of Idaho. She has also been asked to document the spread of the New Zealand mudsnail in the state of Washington. The creature has been found in lakes and other waterways across the state.

    Scientists working with the technology say they do not expect robots to replace field biologists anytime soon. But the old-fashioned field work could soon be more targeted.

    Yesterday I went to the nursing home to visit my grandma. She just got out of the hospital recently where she had some serious operations. I wanted to surprise her after work so I stopped by for a quick visit.

    When I got there she was happy to see me. We hugged, kissed and exchanged greetings. Then I heard a woman crying. It was my grandma's roommate. The curtain was drawn so I could not see her. She started calling out a name that wasn't mine but she was certainly talking to me, begging me to go to her side of the room.

    I ignored her at first and continued visiting with my grandma. Then she started begging and saying, "Please, come to see me!" So I went to see her.

    When I drew the curtain back she looked so old but flashed me the biggest smile! She opened her arms wide for me to hug her so I bent low and gave her a hug. I sat on her bed and talked with her for a few minutes. She kept calling me by the other name but I did not correct her. She told me stories as if I had been there when they happened.

    Finally I went back to talk with my grandma. Then the other woman started crying again, saying, "Please, come back." She finally slept.

    I stopped by the nurse's station and the nurse told me that the lady suffers from Alzheimer's. I mentioned the name she had called me. The nurse told me it was the lady's daughter's name. Then I understood why she wanted me to go to talk with her.

    We will all get old someday. Some of us will have broken minds like my grandma's roommate and some of us will have broken bodies like my grandma. As I was leaving I promised I would go back and visit the lady, even after my grandma moved back to her home.

The ancient Herculaneum scrolls (卷轴)are thought to contain works of important thinkers in ancient Greece. But the scrolls can't be unrolled (打开). Even a light wind threatens to reduce them to dust. The reason is that they were turned into carbon by a natural disaster in A.D. 79.

But now researchers from the University of Kentucky have found a way to look inside the scrolls without having to touch them. They first create a light that is 10 billion times brighter than the sun by taking advantage of a machine. Then they will use the light to go through the Herculaneum scrolls to study and finally read the words recorded on the scrolls. Researchers think it might take them six months to read the scrolls.

This isn't the first time researchers have tried to read the Herculaneum scrolls. Several years ago, scientists from the European Synchrotron Radiation Facility (ESRF) worked on uncovering the mystery using an X-ray beam 100 billion times brighter than anything used in a hospital, This didn't allow scientists to actually read the scrolls, but it allowed them to make one surprising discovery. The scrolls were written in metallic (金属的) ink, a writing technology that scientists didn't know existed at the time the scrolls were penned.

"For a long time, we thought our studies have let us know everything about the ancient ink used to write on scrolls. Now we find it's not the case. This shows that we should tell ourselves it may not be true when thinking we fully know something once some research is done," said Daniel Delattre, one of the study's authors.

The finding wasn't just a historical curiosity. To learn just how special these scrolls are, consider that the thinker Chrysippus in ancient Greece is said to have written over 700 works; but all are lost, with the exception of a few works found in the Herculaneum scrolls. In other words, it's possible that these scrolls represent the only existing complete works left by this great thinker. And who knows what other great works could exist in the scrolls?