How can we bring back lost nutrient   in   the soil without direct application   of   fertilizer?

Explanation:

Crop rotation

Rotation of crop is important to help conserve nutrients that are available in the soil and prevent total use up of the nutrients. The same type of plants all year round on the same soil keeps on draining the land of the same nutrients needed for their growth. Rotation of different can help maintain soil nutrients level as some crop fixes nutrients in the soil.

Natural mulching

The use of cover cops as mulch helps protect the soil and allows for retention of nutrients. When cover crops are harvested the leaves can be turned back into soil to release nutrients that are stored up in the plant part.

Composting is the process of decomposing organic matter this could include animal waste such as dung,leaves both green and dead, kitchen. This waste are stored up, little water is added to moist and then allow to decompose it can be mixed together after few days to aerate after. After decomposing to form compost it can be added to the soil. It is usually rich in nutrients.

the answer is b.) hydrogen bonds between bases.

it should be d) transitional fossils.

they show the gradualism of evolution throughout a period of time