文章大意:本文是一篇说明文。该文章介绍了鱼菜共生系统的工作原理以及它的可持续性。该系统需要监测和保持平衡运行,包括关注鱼的饲料情况、植物的生长情况,以及水的循环情况。
“An aquaponics (鱼菜共生) system grows both fish and plants that can be harvested sustainably (可持续地),” said David Landkamer, an aquaculture specialist. “It’s an elegant system.”
Here’s how it works: Fish are typically raised in indoor tanks or outdoor ponds, where they produce waste. The water with the waste from the tank flows to a planting tray where plants grow in the water without soil. The waste is poisonous to the fish but is a rich fertilizer for the plants. As the plants absorb the nutrients, the water is purified for the fish. The clean water can then be recycled to the fish tank. Most importantly, because you can’t use chemicals or fertilizers that would harm the fish, it’s a natural organic production system.
“You can grow just about any kind of plant,” Landkamer said. Any leafy greens such as lettuce, kale, Swiss chard and arugula are the easiest to plant. You can also grow herbs, cucumbers, snow peas, eggplants, tomatoes, cabbages, cauliflower, peppers, beans, red onions and even potatoes.
“Aquaponics, which began in ancient China and Mexico, is gaining popularity around the world as a means of local food production,” Landkamer said. He regularly fields questions from people who want to start small-scale, backyard aquaponics operations or even commercial-scale aquaponics farms. “It is possible for hobbyists to start out with aquaponics kits available online and at stores,” Landkamer said.
Depending on which species of fish you choose, you may need to add a heater of some kind to keep the water temperatures just right for the fish and plants. “Aquaponics farmers often use inexpensive heat supplies such as solar greenhouses or hot compost (堆肥),” he said.
“These systems require monitoring to make sure everything is in balance and running smoothly,” Landkamer said. “You have to pay attention and see how well the fish are feeding, how well the plants are growing and see whether the water is circulating properly.”
8. What is David Landkamer’s attitude toward aquaponics?
A.Unclear. | B.Cautious. | C.Doubtful. | D.Appreciative. |
9. What is the main advantage of this aquaponics system?
A.It can be set indoors. | B.It produces green food. |
C.It does no harm to the fish. | D.It needs no soil to grow plants. |
10. What does the underlined word “fields” in Paragraph 4 probably mean?
A.Looks up. | B.Keeps off. | C.Deals with. | D.Goes beyond. |
11. What can we know about this system from the last paragraph?
A.It runs automatically. | B.It consumes no energy. |
C.Every part of it must work properly. | D.Its temperature should be high enough. |