Part 3 — Freshwater Resources Crisis (Khủng hoảng tài nguyên nước ngọt)
Bài giảng thực tế từ đề thi VSTEP về tài nguyên nước ngọt — chủ đề môi trường cấp B2. Bài này đòi hỏi khả năng nắm bắt số liệu và hiểu quan hệ nhân quả.
"Today, I'd like to discuss a critical issue facing our planet: the freshwater crisis. Water covers about 71 percent of the Earth's surface, but here's the surprising fact — 97.5 percent of that water is saltwater found in the oceans. Only 2.5 percent is freshwater, and of that small amount, nearly 70 percent is locked away in glaciers and ice caps.
So the freshwater available for human use — in rivers, lakes, and underground aquifers — is actually less than one percent of all the water on Earth. And this tiny fraction must support nearly 8 billion people, plus agriculture, industry, and ecosystems.
The situation is getting worse due to several factors. First, pollution from industrial waste, agricultural runoff, and household sewage contaminates freshwater sources. Rivers that once provided clean drinking water are now too polluted to use safely.
Second, climate change is causing longer and more severe droughts in many regions. Rainfall patterns are shifting, making some areas drier while flooding others.
A dramatic example is Lake Chad in Africa. In the 1960s, it was one of the largest lakes in the world. Today, it has shrunk by approximately 90 percent. Local fish populations have collapsed, and millions of people who depended on the lake for their livelihoods are now facing severe hardship.
Addressing this crisis requires a combination of water conservation, better infrastructure, and international cooperation."
5 câu hỏi trắc nghiệm
Câu 26: What is the main topic of this lecture?
A. Ocean exploration technology
B. How glaciers are formed
C. The benefits of saltwater
D. The global freshwater crisis
Câu 27: What percentage of Earth's water is freshwater?
A. 71 percent
B. 2.5 percent
C. 97.5 percent
D. Less than 1 percent
Câu 28: Which is NOT mentioned as a cause of freshwater problems?
A. Industrial pollution
B. Agricultural runoff
C. Overfishing in rivers
D. Climate change
Câu 29: What happened to Lake Chad?
A. It has shrunk by about 90 percent
B. It has doubled in size
C. It became saltwater
D. It was drained for agriculture
Câu 30: What does the speaker suggest to address the crisis?
A. Water conservation and international cooperation
B. Building more dams only
C. Moving populations to coastal areas
D. Importing water from other planets
Đáp án và giải thích
Câu 26: D — The global freshwater crisis
Mở đầu: "I'd like to discuss a critical issue facing our planet: the freshwater crisis."
Câu 27: B — 2.5 percent
Transcript nói: "Only 2.5 percent is freshwater." Chú ý: 71% là bề mặt Trái Đất có nước, 97.5% là nước mặn, dưới 1% là nước ngọt dùng được.
Câu 28: C — Overfishing in rivers
Transcript đề cập 3 nguyên nhân: ô nhiễm công nghiệp (A), dòng chảy nông nghiệp (B), biến đổi khí hậu (D). "Overfishing" không được nhắc đến như nguyên nhân.
Câu 29: A — It has shrunk by about 90 percent
Transcript nói: "it has shrunk by approximately 90 percent."
Câu 30: A — Water conservation and international cooperation
Kết luận: "a combination of water conservation, better infrastructure, and international cooperation."
Từ vựng quan trọng
| Từ | Nghĩa | Ngữ cảnh trong bài |
|---|---|---|
| freshwater | nước ngọt | only 2.5% is freshwater |
| glacier | sông băng | locked away in glaciers and ice caps |
| aquifer | tầng ngậm nước | underground aquifers |
| runoff | dòng chảy (ô nhiễm) | agricultural runoff contaminates water |
| drought | hạn hán | longer and more severe droughts |
| shrunk | thu hẹp | Lake Chad has shrunk by 90% |