How much do you know about them? Is the economy there well-developed or not?
Which city is the most developed? Why?
Can you tell what map it is? Where is it? Is the water here salty or fresh? What’s the place where river and the ocean meet?
Find the definition of an estuary
An estuary is the body of water where a river meets the ocean. Salt water from the ocean and fresh water from the river mix together in an estuary. This mixing of fresh and salt water creates a unique environment filled with life of all kinds－a zone between the land and sea.
What kinds of function of estuaries have been mentioned in the passage?
Great places for nature’s young animals clean our water by absorbing nutrients and pollutants from water coming from inland sources; Provide both recreation and education for human beings.
What living conditions do you think are needed for nature’s young ones?
Do estuaries have such conditions for them?
Read the passage and answer the following questions.
1. Why are estuaries such good places for nature’s young ones?
In estuaries, animals can enjoy all the benefits of the oceans without having to face many of its dangers. Tides provide energy for the ecosystems, but estuaries are protected from waves and storms by islands, mud or sand. Nutrients from both the land and the ocean arrive in estuaries.
2. What does density mean in this passage?
It means the number of species per area.
3. How do you estuaries affect the water that passes through them?
They absorb nutrients and pollutants from water coming inland sources, thus cleaning our water.
4. Why are estuaries more sensitive to pollution than other areas?
Because estuaries act as filters(过滤器), many pollutants end up in them.
5. Why are estuaries important to human beings? ① Estuaries provide both recreation and education for human beings.
People can fish, swim and have fun on the beach. Scientists and students have endless opportunities to study a variety of life in the habitat.
② Estuaries also contribute to the economy through tourism and fishing.
Finish the following passage with words from the text.
Estuaries are bodies of water along coasts that are ________ forme (形成) when fresh water mixes with salt from rivers d flows into and ________ water from the ocean. In estuaries, the fresh river water is blocked from streaming into the open ocean by either surrounding mainland, or islands. This mixing of fresh and salt water _______ creates a unique environment ______ filled with life of all kinds — a zone between the land and sea known as an estuary.
The estuary gathers and holds a ________ variety of life －giving nutrients from the land and from the ocean, forming an ecosystem that contains more creatures than any other ________ habitat on the earth. Estuaries are also important for human beings. They protect water quality by absorbing ________ pollutants from water coming from inland sources. They are centers for ________________ entertainment (娱乐) and education. Estuaries, in short, are treasures.
If you are describing a process,
? You should explain each step in the order it happens.
? Tell the readers about the causes and effects and use words like first, second, then, etc to show the order of the steps. ? First… ? Second… ? Third/ Then… ? Last…
If you are writing about something that has several parts, describe each part and explain its function and structure.
The following questions may help: ? What is it ? How many parts is it made up of? ? What‘s the structure of each part? How does it work? ? What’s the function of the thing?
Imagine that your science teacher ask you to explain one of the following questions:
Why does an ice cube float?
What will happen to a piece of metal if you put it in water? Why do so many species live in estuaries? Why have so many cities been built by estuaries?
Choose one of the questions and write a passage, using what you know about nature and science and what you have learned from this unit.
Choose one of the questions and write a passage, using what you have learned about water from this unit and new words and sentence structures of this unit as well.