Reading comprehension -TOEFL- Lesson 145 (Đọc hiểu -TOEFL- Bài 145)
Đọc đoạn văn sau và trả lời các câu hỏi:
Fog occurs when damp air above the surface of the earth is cooled to the point at which it condenses. Of the two types of fog, advection fog occurs along the ocean coast or near rivers or lakes. This type of fast-moving fog, which may cover vast areas, occurs when warm 5 winds blow across a cold surface of land or water. In this collision of heat and cold, the warm air is cooled to the point at which the water vapor condenses into fog. Radiation fog, quite different from advection fog, is immobile cloud-like moisture generally found hovering over wintertime valleys. It occurs on clear nights when the earth's 10 warmth escapes into the upper atmosphere.
1. According to the passage, fog is found when wetness in the air is
2. According to the passage, advection fog is found
3. In the passage, radiation fog is said to be
4. According to the passage, which of the following statements about fog is true?
5. The author's purpose in this passage is to
