Find out the correct sentence about manure:
$(i)$ Manure contains large quantities of organic matter and small quantities of nutrients.
$(ii)$ It increases the water holding capacity of sandy soil.
$(iii)$ It helps in draining out of excess of water from clayey soil.
$(iv)$ Its excessive use pollutes environment because it is made of animal excretory waste.

To get a better yield,Jaikishan increased the use of pesticides and fertilizers. Though in the initial years he got higher yield,after that,it declined. He was much worried. His friend Mahesh persuaded him to abandon this practice and start using organic manure.
$(i)$ Why are fertilizers used in a field?
$(ii)$ State the possible reason for the decline in yield.
$(iii)$ List two values shown by Mahesh.

$(i)$ State three ways by which pests attack plants.
$(ii)$ Name the chemicals used to control pests.
$(iii)$ Explain why excessive use of such chemicals should be avoided.

Once Ravi and Aman were cooking rice in the kitchen and accidentally Aman's hand got a severe burn while opening the lid of the cooking vessel. Immediately,Ravi applied ice on his hand,then applied an ointment,and told him to cook carefully as he had been hurt by steam,and steam causes more severe burns. Aman thanked Ravi and smiled.
$(a)$ According to you,what kind of qualities are shown by Ravi?
$(b)$ How does steam produce more severe burns than boiling water?

Two average students, Ram and Shyam, were discussing the following graphs in the class:
[Image: $1158-196$]
The question relating to the graphs was to identify which one of them was not possible. Ram and Shyam agreed that graphs $A, B$ and $C$ were not possible. But Shyam said that graph $D$ is possible, while Ram said that it is also not possible. Since their teacher was on leave, they could not ask her. Seeing this, Ratan, who was very intelligent, came to their rescue. He told Shyam that graph $D$ was also not possible.
$(a)$ Do you think that Ratan is right? If so, why is graph $D$ not possible?
$(b)$ What values are imbibed by Ratan?

Which one of the following fish variety is a surface feeder?