Name two protein-containing rabi crops.

Raman lives in a coastal village. He is the son of a fisherman. Whenever any unwanted animal comes in the net,instead of killing it,he puts it back in the sea.
$(a)$ What would have happened,had he killed those animals?
$(b)$ Give one reason to justify that Raman's action is environment-friendly.
$(c)$ How can you contribute to the preservation of flora and fauna around you? Mention any two steps.

Why is excess use of fertilizers detrimental for the environment?

Which one of the following nutrients is not available in fertilizers?

Dalton was the first scientist to use symbols for elements. Chemical symbols act as a vocabulary of chemical language. Chemical symbols are used to describe chemical changes with clarity and precision. Chemical symbols help in identifying specific elements. Chemical symbols also represent an atom of a particular element. Chemical symbols also signify the atomic mass of an element.
$(a)$ How do symbols help in identifying specific elements?
$(b)$ How do we use symbols in daily life for our convenience?
$(c)$ What values do you find in using symbols?

Arrange these statements in the correct sequence for the preparation of green manure.
$(a)$ Green plants are decomposed in the soil.
$(b)$ Green plants are cultivated for preparing manure or crop plant parts are used.
$(c)$ Plants are ploughed and mixed into the soil.
$(d)$ After decomposition,it becomes green manure.