China has been planting seaweed for about 1,700 years . Coastal populations harvested a variety of algae first as a source of food and animal feed, but later for industrial and nutritional purposes as the practice became more widespread- Today, China remains the world’s biggest producer of farmed seaweed, but many other countries start to realize the potential of planting seaweed.

Certain red seaweed varieties contain up to 25% protein, but others are also rich in iron and other minerals. Seaweed planting becomes hot aquaculture which is now shooting up. In Alaska, where the largest seaweed farm in North America is located, farmers produced over 112,000 pounds of seaweed in 2019 — a 200% increase from Alaska’s first commercial harvest in 2017. Occupying just a few acres, seaweed planting is economical, relatively simple and comes with a lot of environmental benefits.

Research shows that seaweed could play a key role beyond serving as a source of nutrients and food, but also in the fight against some of the worst problems: climate change and ocean pollution. Seaweed doesn’t need to be fed or fertilized, as the crop gets everything it needs from sunlight and the natural nutrients already found in the ocean water. There are, of course, some disadvantages to seaweed farming. For example, overproducing seaweed could influence the amount of natural light available to other ocean species. In addition, technology for transporting, drying, and turning seaweed into biofuel and food can take up resources and give off CO₂. It’s also possible that these crops could remove too many nutrients from the wild ecosystem.

However, as research continues to search into sustainable seaweed farming methods, we may discover that advantages win over disadvantages.

The economic value of dealing with nutrient pollution, for example, may reduce costs for wastewater treatment; the same goes for turning seaweed into biofuel, fertilizer, or fuel depending on water quality. The balance will come down to a combination of policy and scientific research .

【小题1】Why does the author mention seaweed farming in Alaska?

A．To show seaweed planting is growing fast.

B．To announce seaweed planting is eco-friendly.

C．To state seaweed is easy to plant across the world.

D．To prove seaweed planting has large economic benefits .

【小题2】Which is the disadvantage of seaweed planting?

A．Removing other ocean species.	B．Consuming too many nutrients.
C．Taking up too much space.	D．Causing potential ocean pollution.

【小题3】How is paragraph 3 mainly developed?

A．By making a comparison.	B．By providing evidence.
C．By using classifications.	D．By analyzing the background.

【小题4】What can we infer about seaweed farming in the last paragraph?

A．There are arguments over it.	B．Turning seaweed into fuel is necessary.
C．It needs joint efforts to improve.	D．Dealing with nutrient pollution costs a lot.