In a village, farmers started cultivating crops all around a lake which was always filled with water. They added lot of materials W to the soil in their fields to increase the yield of crops. Soon they found that the whole surface of water in the lake was covered with a green layer made up of tiny organisms X. After some time, the fish present in the lake started dying in large numbers because they could not get sufficient Y due to a process Z which had occurred in lake water and drained out all the Y present in the water of lake.

Options

A. What do you think materials Ware?
B. Name (2) X, and (ii) Y.
C. What is the process Z known as ?
D. What happens during the process Z which uses up all the Y present in lake water?
(E) What does this example tell us about the use of materials like W ?

Explanation

To solve the question step by step, we need to identify the materials and processes involved in the scenario described.

### Step-by-Step Solution:

1. **Identify Material W**:
- The farmers added a lot of materials to the soil to increase crop yield. This material is likely to be **fertilizers**. Fertilizers are commonly used to enhance soil fertility and boost crop production.

**Hint**: Think about what substances farmers commonly use to improve soil quality and crop growth.
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