1 . Under a midday summer sun in California’s Sacramento Valley, rice farmer Peter Rystrom walks across a dusty and bare plot of land, dry soil crunching (碎裂) beneath each step. In a typical year, he’d be walking across green rice fields in inches of water. But today the soil is dry and baking in the 35℃ heat. It hasn’t rained for 4 weeks in a row.
“Climate change is expected to worsen the state’s extreme swings in rainfall,” researchers reported in Nature Climate Change in 2018. Low water levels in rivers have forced farmers like Rystrom, whose family has been growing rice on this land for four generations, to reduce their water use.
“If we lose our rice crops, we have to deal with severe food crisis. Climate change is already threatening rice-growing regions around the world. This is not a future problem. This is happening now,” says plant geneticist Pamela Ronald of the University of California, Davis, who identifies genes in rice that help the plant stand up to dryness, disease, flood, etc.
To save and even boost production, rice growers, engineers and researchers have turned to water-saving irrigation (灌溉) routines. Building canal systems and reservoirs (水库) can help farmers dampen their fields. But for some, the solution to rice’s climate-related problems lies in enhancing the plant itself. They hold that establishing rice gene banks that store hundreds of thousands of rice varieties ready to be bred into new, dryness-tolerant varieties is more practical and effective. Solutions may be hidden in the DNA of those older breeds.
Three decades have passed since its initial development, and some researchers are looking beyond the genetic variability preserved in rice gene banks, searching instead for useful genes from other species, including plants and bacteria. But picking genes from one species and putting them into another, or genetic recombination, remains debatable. The most famous example of genetically changed rice is Golden Rice (GR). “Looking ahead, it will be crucial for countries to embrace GR rice. But it will take time,” says Ismail, principal scientist at IRRI,
1. What problem does Rystrom have to deal with?| A．Thirst. | B．Drought. | C．Hot sun. | D．Dusty weather. |
| A．Downtrend of rice-growing areas is severe now. |
| B．Climate change is a threatening factor in the future. |
| C．Humans will face starvation if crop failure happens. |
| D．Food crisis is a common occurrence around the world. |
| A．To store as many seeds as possible. | B．To cultivate climate-adapted varieties. |
| C．To improve the efficiency of breeding. | D．To show the technology of gene mapping. |
| A．Favourable. | B．Impractical. | C．Disapproving. | D．Insecure. |
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. |
