Weeds affect the crop plants by:

Balwinder was a small farmer. As his field was rain-fed,he could not take the risk of growing specialized crops. He used to mix the seeds of two crops and sow them in the field. Kaku,his son who passed class $IX$,suggested growing two or more crops simultaneously in a definite pattern. Balwinder followed this,and the productivity per unit area increased.
$(i)$ Name the cropping pattern which Balwinder used earlier and the one suggested by Kaku.
$(ii)$ Write two advantages of practicing the pattern suggested by Kaku.
$(iii)$ Write two values displayed by Kaku.

Bhetki,mullets,pearl spots and prawns are some of marine fish of high economic value.

$(a)$ State two differences between egg layers and broilers.
$(b)$ How can poultry fowl be prevented from various diseases? State any three methods.

$(a)$ Mention the harmful effects of infectious diseases on the health of cattle.
$(b)$ How can these diseases be controlled?

Mention the basis of crop selection in intercropping and crop-rotation.