Every electronic gadget needs good memory. A music player stores songs, albums and playlists. A computer holds schoolwork and programs and remembers how far a player has advanced in his or her favorite game. Mobile phones store names, numbers and hundreds of texts. Now, scientists in California say they have come up with a way to turn a living cell into a memory device. It can store only one tiny bit of information, but it's a start. In the future, a cell-based gadget might travel through the body and record measurements. The benefit to human health could be big: the right tool, for example, might record the earliest signs of disease. Doctors, scientists and other curious people want to know what is happening inside the body, even at levels that can't be seen by the naked eye. So far, there is no device small enough to travel through the bloodstream. If normal machines won't do the trick, perhaps biology will. Scientists who work in the field of synthetic biology are trying to find ways to turn living things into human tools. In the case of the new memory device, bioengineers from Stanford University used the genetic material inside living cells to record information. This genetic material consists of DNA. Found in nearly every cell, DNA carries all of the information that keeps a living thing alive. In the new experiment, the researchers turned DNA from bacteria into a switch. They "flip " a small section of DNA. Then, using the same procedure , the scientists flip the section again--returning it into its normal structure. Using these DNA switches, "We can write and erase DNA in a living cell," bioengineer, Jerome Bonnet, explained to Science News. It might take years before his team or others identity whether a DNA-based memory device might be practical. Right now, it takes one hour to complete a flip. That is far too long to be useful. Plus, a flipped section has a very small little memory--less than what a computer uses to remember a single letter. "This was an important proof that it was doable,"... What do we know about a flipped section of DNA? A) It has a very small memory. B) It can function as a computer. C) It has one letter in it. D) It takes a day to complete it.
A
I climbed the ladder, heard my dive announced, and began the moves that would push me into the air. Pushing off the diving board with my legs, I lifted my arms and shoulders back, and knew immediately I would be close to the board and might hit my hands. I tried to correct myself as I turned, spreading my hands wide apart. Then I heard a strange sound and my body lost control. Moments later I realized I had hit my head on the board. At the beginning, I felt embarrassed. I wanted to hide, to get out of the pool without anyone seeing me. Next I felt intense fear. Had I cut my head? Was I bleeding? Was there blood in the pool? Swimming to the side, I noticed many shocked faces. People were worried about my head; I was worried about something far more threatening. An official examined my head. In a hurry, I pushed him away, and everyone else who approached me. "Don't touch me!" I felt like screaming. "Get away from me!" These were the trials for the 1988 Olympics in Seoul, Korea. Until this dive, I had been ahead. But now, something else was more significant than winning. I might have endangered other divers' lives if I had spilled blood in the pool. For what I knew--- that few others knew - was that I was HIV-positive. According to my mother, my natural parents were Samoan and only teenagers when I was born, so they gave me up for adoption. When I was only eighteen months old, I started gym classes. At ten, I explored doing gym exercises off the diving board at the pool. Because of my dark skin, kids at school called me names. My diving made me feel good about myself when my peers made me feel stupid. At sixteen, I knew I had a shot at the 1976 Olympics. Everyone was alarmed when I hit my head on the board in Seoul. Regardless, I made it to the finals. During my last dive in the finals, I enjoyed for the last time the quietness underwater and then swam to the side of the pool. The crowd cheered, and I knew I'd won --- two gold medals. AIDS forced me to stop diving; I had to give up diving professionally... Immediately before he hit his head on the board, the writer _ . A) climbed the ladder B) started the moves that would push him into the air C) knew he was too close to the board D) corrected his actions when he turned
D
(Question)
Women who own cats are more likely to have mental health problems and kill themselves because they can be infected by a common parasite that can be caught from cat litter, a study has found. Researchers found women infected with the Toxoplasma gondii (T. gondii) parasite , which is spread through contact with cat waste or eating undercooked meat or unwashed vegetables, are at increased risk of attempting suicide. The study involved more than 45,000 women in Denmark. About a third of the world's population is infected with the parasite, which hides in cells in the brain and muscles, often without producing symptoms. The infection, which is called toxoplasmosis , has been linked to mental illness, such as schizophrenia , and changes in behavior. The study's senior author Doctor Teodor Postolache, an associate professor of psychiatry at the University of Maryland School of Medicine in the United States, said, "We can't say with certainty that T. gondii caused the women to try to kill themselves, but we did find a predictive association between the infection and suicide attempts later in life that deserves additional studies." Doctor Albert Reece, vice president of medical affairs at the University of Maryland, said, "T. gondii infection is a major public health problem around the world, and many people don't realize they're infected. "Dr Postolache is a leading expert on suicide neuroimmunology . Suicide is a critically important mental health issue. About one million people commit suicide and another 10 million attempt suicide worldwide each year. We hope that this type of research will one day help us find ways to save many lives that now end too early in suicide." Dr. Postolache's research team at the University of Maryland was the first to report a connection between T. gondii and suicidal behavior in 2009. He is cooperating with researchers in Denmark, Germany and Sweden to confirm and investigate the way leading to this association. The T. gondii parasite thrives in the intestines of cats, and it is... What is the consequence if a woman is infected with the parasite in the passage? A) Having a high fever. B) Doing deliberate self-harm. C) Keeping a depressed mood. D) Becoming bad tempered. 53.
(Answer)
B