1. (2023高二上·尚志月考) 阅读理解

The twilight zone (朦胧地带) contains the largest and least explored fish stocks (储备) of the world's oceans. Ranging from just below 200 metres to 1,000 metres deep, it is an interface between the well-studied sea life in the sunlit zone above and the ecosystems of the darkest territory below. It has a major role in removing carbon dioxide from the atmosphere and storing it for centuries or longer. The twilight zone is also known to the largest migration on Earth. Huge numbers of fishes and zooplankton (浮游动物) move hundreds of metres towards the surface each night to feed, before withdrawing back down at dawn.

Yet the zone is poorly understood — physically, biogeochemically and ecologically. Even the number of organisms that live there remains a mystery, let alone their diversity and function.

It is alarming, then, that this vast ocean domain is at risk in three ways-even before any of the potential consequences are understood. First, the world's growing population has an increasing need for food. Second, sea-floor mining for minerals and metals could release waste into the region. And third, climate change is varying temperature, acidification and oxygen levels in ways that are likely to affect life there.

The twilight zone is hard Io study. Its organisms are difficult to sample and analyse, being thinly distributed, almost invisible and often fragile. They also live at pressures of up to 100 atmospheres, which poses problems for laboratory-based investigations.

Critics might argue that waters near coasts and above shelves are more deserving of study, given the huge environmental pressures there, as well as their importance to societies. And, of course, they need attention. Sadly, however, it is too late to avoid widespread environmental damage to these inshore regions. Instead, research efforts and local policies must aim at minimizing the worst effects.

By contrast, the twilight zone is almost left in its original condition. Moreover, the majority of it lies beyond national administration. This makes it of common interest and responsibility, and means that global agreement is necessary to manage it.

1. （1） What can we learn about the twilight zone?

   A . It has the least fish stocks. B . It reduces atmosphere's carbon dioxide. C . It lies at the bottom of sea. D . It is located above the sunlit zone.
3. （2） What does Paragraph 3 mainly tell us?

   A . Where global warming leads us. B . Why high food consumption arises. C . How the twilight zone is threatened. D . What impacts pollution has on ocean.
5. （3） What does the underlined word "it" in the last paragraph refer to?

   A . The twilight zone. B . The inshore area. C . Its original condition. D . National administration.
7. （4） Which statement does the author agree with?

   A . International cooperation is essential. B . Inshore regions deserve more attention. C . Global agreement has been reached. D . Study on the twilight zone is out of the question.