Freshwater resources include canals,ponds,reservoirs and rivers.

Vividha told Vasudha that she will show her some magic. Vividha took a metallic pipe. She asked Vasudha to hold one of its ends close to her ears. She gently tapped the other end of the pipe with a metallic object. She asked Vasudha what she heard. Vasudha said she heard two sounds.
$(a)$ Was this magic? Why did Vasudha hear two sounds?
$(b)$ What values are imbibed by Vividha?

Name the two vitamins which are added in the poultry feed.

Which one of the following fishes is a surface feeder?

Write three advantages of crops growing in shorter duration of time compared to those growing in longer duration of time.

Sitaram,an educated farmer,convinces his friends to use manure instead of fertilizers in their fields. List any two advantages that the farmers will get if they accept this advice. How does the excessive use of fertilizers affect the environment? Which values of Sitaram are depicted by his efforts?