Four phrases/sentences have been removed from the text below. For each question, mark the letter A, B, C, or D on your answer sheet to indicate the correct option that best fits each of the numbered blanks.
Supervolcanoes are probably the most destructive force on the planet. There aren't many of them, but (1)__________.
The largest supervolcano eruption happened about 74,000 years ago in Lake Toba, Sumatra. The eruption was so huge that the ground was covered with 35cm of ash as far as 2,500km away from the volcano. The blast also had a huge effect on global temperatures which dropped by around 5°C. This drop in temperature was devastating and scientists have discovered that (2)__________.
Supervolcanoes differ from normal ones in many ways. A normal volcano is cone-shaped and when it erupts the lava bursts out of the top and flows down the sides. On the other hand, supervolcanoes form underground. (3)__________.
One of the largest supervolcanoes that exists today is in Yellowstone National Park, USA. When scientists were doing research on the volcano they were really surprised by what they found. Basically, the whole of the park had a massive pool of magma underneath it, measuring 70km across by 30km wide! Moreover, they discovered evidence to suggest that the Yellowstone supervolcano erupts every 600,000 years. (4) __________.
A. it caused the summers in Europe to be freezing cold and also had a catastrophic effect on animals and plant lite
B. Unfortunately, its last eruption was well over 600,000 years ago, so it seems that the clock is ticking
C. if one erupts it would almost certainly threaten the survival of the human race
D. Magma slowly rises from a hotspot deep down in the earth, until eventually hundreds of thousands of years later an enormous blast occurs
Lời giải chi tiết
Để chọn đáp án đúng, các em cần chú ý đến ngữ pháp cũng như sự logic của văn cảnh. Các từ khóa trong các câu cần khớp với ngữ nghĩa chung của cả đoạn văn để giúp hiểu và xác định vị trí thích hợp cho từng chữ cái cần điền.
1. Vị trí (1): "There aren't many of them, but ________."
Trong câu này, "them" đề cập tới "supervolcanoes". Chúng ta cần một vế bổ sung thông tin về tác động lớn của supervolcanoes. Do đó, option C "if one erupts it would almost certainly threaten the survival of the human race" là phù hợp nhất. Nó nhấn mạnh sức phá hủy tiềm tàng của một vụ phun trào supervolcano.
2. Vị trí (2): "scientists have discovered that ________."
Trước đó, văn bản đề cập việc nhiệt độ toàn cầu hạ thấp do vụ phun trào. Điều này có tác động lớn đến môi trường và sự sống, do đó option A "it caused the summers in Europe to be freezing cold and also had a catastrophic effect on animals and plant life" hợp lý để nối tiếp ý này.
3. Vị trí (3): "Supervolcanoes form underground. ________."
Câu này cần một diễn giải cụ thể về cách supervolcanoes hình thành dưới lòng đất. Option D "Magma slowly rises from a hotspot deep down in the earth, until eventually hundreds of thousands of years later an enormous blast occurs" phù hợp nhất.
4. Vị trí (4): "Moreover, they discovered evidence to suggest that the Yellowstone supervolcano erupts every 600,000 years. ________."
Câu này cần một câu nối tiếp để diễn tả hậu quả do volcano đã quá hạn phun trào. Vì thế, option B "Unfortunately, its last eruption was well over 600,000 years ago, so it seems that the clock is ticking" là đáp ứng yêu cầu của đoạn văn để chỉ ra mức độ nghiêm trọng của tình huống.
(1) C: Supervolcanoes are probably the most destructive force on the planet. There aren't many of them, but if one erupts it would almost certainly threaten the survival of the human race.
(2) A: This drop in temperature was devastating and scientists have discovered that it caused the summers in Europe to be freezing cold and also had a catastrophic effect on animals and plant life.
(3) D: Supervolcanoes form underground. Magma slowly rises from a hotspot deep down in the earth, until eventually hundreds of thousands of years later an enormous blast occurs.
(4) B: Moreover, they discovered evidence to suggest that the Yellowstone supervolcano erupts every 600,000 years. Unfortunately, its last eruption was well over 600,000 years ago, so it seems that the clock is ticking.
Đáp án lần lượt là: (1) C, (2) A, (3) D, (4) B.
Chú ý khi giải