Positive ions from a base and negative ions from an acid form a it helps for example ypu have positive ions right well take my smart advice well the positive ions and the negative ions they combine together to make sulphour
Answer:
The correct answer will be- Crop rotation
Explanation:
When the growth of a type of crop which uses soil nutrients in abundance and then growing another crop in the same filed led to the decrease in the production of the next crop.
Thus farmers adapted to avoid such farming practices and developed a new practice which allowed the land to become fertile again so that the growth of next crop will not be affected.
The practice involved the planting of a crop on a piece of land then leaving the soil ploughed and unsown for a longer period of time and growing corp on another piece of land allowing the time to restore the nutrient content. This practice is known as "crop rotation".
Thus, crop rotation is the correct answer.
There are a couple reasons the ice is important to polar bears, but given the choices you have the correct one would be:
A. The polar bears can’t out swim the seals, so they sit quietly on an ice platform and attack the seals when they come up for air.