题型：语法填空（语篇） 题类：常考题 难易度：困难
湖北省武汉市部分学校2020届高三上学期英语起点质量监测试卷
What makes the sea tum red and causes thousands of fish to die？As far back as anyone could remember, the blame was placed on the "red tides." In 1947, scientists finally connected the red tides with a microscopic sea organism(有机体)(call)the dinoflagellate.
The dinoflagellate is so tiny 6, 000 of these organisms may be contained in single drop of water. It stands on the borderline between plant and animal in its classification, it produces its own food, as plants do. But it moves (free)and eats other organisms, as animals do.
Dinoflagellates are normally only one of the many kinds of organisms found in plankton. Plankton is the name given to all very small (form)of sea life. However, when the air and water (be)calm and warm, dinoflagellates multiply with (amaze)sped. The surface of the water appears (cover)with a red carpet.
The dinoflagellates give off a poison. Many fish die. Their bodies are washed up on the beach. Beaches are not fit any use. Fish that are not killed may become (poison)to animals or people who eat them. Commercial fishing comes to a stop.
As dinoflagellates consume all the food and oxygen in an area, they die. After a time, the sea returns to normal. But when conditions are right, the red tide comes again.
试题篮
