1 . Plant biologists have found a way that may enable poor farmers to do away with the need to purchase expensive hybrid seeds every year. Researchers at the University of California report that they have solved a long-standing problem of hybrid seeds by making exact clones of the hybrid plants from seeds.
For long, many crops have been grown from high-yielding, anti-disease or climate-tolerant hybrid seeds. But the seeds of hybrid crops do not produce plants with the same qualities during reproduction and hence farmers cannot save the seeds for the next growing season. They end up paying for new hybrid seeds each sowing season. The discovery, long sought by plant researchers, could make it easier to grow desirable high-yielding crops and make them available to the world’s farmers. Farmers could thus replant seeds from their own hybrid plants and enjoy the benefits of high production year after year, the scientists report.
While the discovery would help farmers, it would also impact the commercial interest of the hybrid seed industry. Siddiq, a former Deputy Director General in the Crop Science Division of the ICAR, said at first sight, this might seem like a setback for hybrid seed companies but there would be plenty of things they can still do. “Rice is grown over such a vast climatic and geographical range that specialized hybrids would have to be developed for each region,” he said. The companies, he said, would continue to improve their hybrids. “It will be interesting to see how all this plays out in the years to come.”
Currently, the high costs of producing hybrid seeds are a major barrier to farmers in developing countries, especially South Asia and Africa. Siddiq said if efficiently used, this method could potentially be a game-changer for poor farmers, who would need to purchase hybrid seeds just once and plant the progeny(后代) seeds from their own harvest in the following seasons.
1. What problem do the researchers aim to solve?| A．Farmers’ income. | B．Farmers’ costs. |
| C．Hybrid seeds’ cloning. | D．Hybrid seeds’ climate tolerance. |
| A．They have a pretty long growth cycle. |
| B．They tend to be affected by various diseases. |
| C．They have stricter requirements for sowing time. |
| D．They fail to reproduce plants with the same quality. |
| A．Hopeful. | B．Concerned. | C．Doubtful. | D．Anxious. |
| A．The future of the hybrid seed industry. |
| B．The drawback of cloning hybrid seeds. |
| C．A method of cloning hybrid plants from their seeds. |
| D．A means of promoting the specialized hybrid seeds. |
2 . What if someone told you about a kind of grass as tall as the tallest trees? A grass as strong as steel? Would you believe that person? You should, for that grass is bamboo (竹子), which has more than 1,000 uses. It is not just a material for making useful products. Young bamboo is eaten, often mixed with other vegetables.
Bamboo grows in many parts of the world. In the USA it grows in many states like Virginia and Florida. Most bamboo, however, is found in wet and warm climates, especially in Asia and on the islands of the South Pacific Ocean.
In most Asian countries, bamboo is nearly as important as rice. This unusual material is used to not only build large buildings but also make water pipes, musical instruments and paper. There are over 1,000 kinds of bamboo. No wonder the lives of nearly half the people on earth would change greatly if there were no longer any bamboo.
1. According to the text, bamboo is actually a kind of .| A．grass | B．steel | C．tree | D．vegetable |
| A．Only in Asia. | B．Only in the USA. |
| C．In wet and warm climates. | D．All over the world. |
| A．Build large buildings. | B．Make water pipes. |
| C．Make musical instruments and paper. | D．All of the above. |
| A．Over 1,000. | B．Over 800. | C．Over 600. | D．Over 400. |
3 . A few weeks ago, I received a package containing a small batch (一批) of seeds from my friend. When I asked her what it would grow
I sowed the seeds in a beautiful flowerpot. In the first few days, I was excited to search for the slightest
I watered the plant carefully. I placed the plant in the sunlight and rotated (旋转) it for a
Bending down and carefully studying the seedlings, I could almost
Now they are taller than the edge of the pot,
I am certain that after a few more days, my coriander plants will be ready for
| A．into | B．for | C．up | D．out |
| A．gradually | B．incredibly | C．ultimately | D．intently |
| A．samples | B．signs | C．routes | D．proofs |
| A．apparent | B．distinct | C．conventional | D．massive |
| A．allowed for | B．longed for | C．provided for | D．went for |
| A．intense | B．violent | C．balanced | D．exceptional |
| A．emerged | B．hatched | C．reserved | D．sank |
| A．pray | B．assess | C．forecast | D．hear |
| A．conflicted | B．facilitated | C．crowded | D．surrounded |
| A．subsequently | B．constantly | C．extensively | D．merely |
| A．howl | B．scream | C．thunder | D．whisper |
| A．initiative | B．leisure | C．harmony | D．luxury |
| A．possession | B．consumption | C．exposure | D．harvest |
| A．breaking into | B．relating to | C．brightening up | D．wearing down |
| A．touch | B．bunch | C．host | D．lot |
4 . For many people, catching a smell of freshly cut grass is a pleasant sign that warmer weather is here to stay. For the grass, however, this scent signals an entirely different story.
The smell we associate with freshly cut grass is actually a chemical SOS, one used by plants to beg nearby creatures to save them from attack. After all, when danger strikes —whether it's gardening equipment or a hungry caterpillar — plants can't lift their roots and run. They must fight where they stand. To protect themselves, plants employ a string of molecular (分子) responses. These chemical communications can be used to poison an enemy, warn surrounding plants of dangers or attract helpful insects to perform needed services.
Clearly, plants can communicate. But does that mean they can feel pain? According to some researchers, plants release gases that are the equivalent of crying out in pain. Using a laser-powered microphone, researchers have picked up sound waves produced by plants releasing gases when cut or injured. Although not audible to the human ear, the secret voices of plants have revealed that cucumbers scream when they are sick, and flowers cry when their leaves are cut.
There's also evidence that plants can hear themselves being eaten. Researches show that plants understand and respond to chewing sounds made by caterpillars dining on them. As soon as the plants hear the noises, they respond with several defense mechanisms.
For some researchers, evidence of these complex communication systems — giving out noises via gas when in pain — signals that plants feel pain. Others argue that there cannot be pain without a brain to register the feeling. Still more scientists infer that plants can exhibit intelligent behavior without possessing a brain or conscious awareness.
As they grow, plants can change their paths to avoid obstacles or reach for support with their tendrils (卷须). This activity comes from a complex biological network distributed through the plants' roots, leaves and stems. This network helps plants reproduce, grow and survive.
1. What does the smell of freshly cut grass signal?| A．Warmer weather. | B．Being poisonous. |
| C．Cry for help. | D．The need of services. |
| A．By giving out gases. | B．By changing the color of their leaves. |
| C．By producing audible sound waves. | D．By sharing it through the root systems. |
| A．Their tendrils. | B．Their biological network. |
| C．Their communication systems. | D．Their conscious awareness. |
| A．Do plants feel pain? | B．How plants protect themselves? |
| C．Do plants communicate? | D．How plants grow and reproduce? |
