Choose the letter A, B, C or D to complete the passage below
Water pollution happens __________ (1) toxic substances enter water bodies such as lakes, rivers, oceans and so on, getting dissolved in them, lying suspended in the water or depositing on the bed. This degrades the quality of water. Not __________ (2) does this spell disaster for aquatic ecosystems, the pollutants also seep through and reach the groundwater, which might end up in our households as contaminated water we use in our daily activities, including drinking.
Water pollution can be __________ (3) in a number of ways, one of the most polluting being city sewage and industrial waste discharge. Indirect sources __________ (4) water pollution include contaminants that enter the water supply from soils or groundwater systems and from the atmosphere via rain.
Question 3:
A. cause
B. caused
C. causing
D. causes
Đáp án: B
Giải thích: be caused: được tạo ra, bị gây ra
Dịch: Ô nhiễm nước có thể được tạo ra từ nhiều cách, một trong những tác nhân lớn nhất là nước thải đô thị, và chất thải công nghiệp.