Petroleum was formed from organisms living in the sea. As these organisms died, their bodies settled down at the bottom of the sea and got covered with sand and clay. The absence of air, high pressure and high temperature for over millions of years transformed the dead organisms into petroleum and natural gas. The petroleum deposits are usually found mixed with salt water. The petroleum is lighter than salt water, and hence, floats over it.
Select the correct word from the following list and fill in the blanks.
float, water, crop, nutrients, preparation
| A | B | ||
|---|---|---|---|
| (i) | Kharif crops | (a) | Food for cattle |
| (ii) | Rabi crops | (b) | Urea and super phosphate |
| (iii) | Chemical fertilizers | (c) | Animal excreta, cow dung urine and plant waste |
| (iv) | Organic manure | (d) | Wheat, gram, pea |
| (e) | Paddy and maize | ||