Chapter 17: Here Comes a Letter

1. The postman unlocks the red postbox, collects all letters in a canvas bag, and takes them to the Head Post Office.
2. Letters are stamped with the post office seal date and sorted according to destination PIN codes.
3. Bundled letters are loaded onto mail vans, trains, or aeroplanes to reach the destination city.
4. At the destination delivery post office, the local beat postman sorts the letters street by street and delivers them into recipients' letterboxes.

A PIN code (Postal Index Number) is a 6-digit numerical code used by India Post. Each digit represents a specific geographic zone, sub-region, sorting district, and delivery post office. Writing the PIN code ensures that automated machines and sorters can route the letter quickly without errors caused by confusing handwriting or duplicate village names.

People sent urgent messages through the Telegram (which transmitted short coded electrical signals over wires in hours) or through carrier pigeons and horseback royal couriers (harkaras) in ancient times.

Journey of a Letter:
1. Reena writes the letter, pastes a postal stamp, writes Ahmed's complete address with PIN code, and drops it into the red Letter Box.
2. The postman opens the letter box with a key, collects all letters in a canvas bag, and takes them to the local Head Post Office.
3. In the post office, clerks stamp the date and sort letters by destination city, loading Delhi sacks onto the mail van of a Train.
4. At Delhi Railway Station, the mail van delivers the bags to the Delhi Post Office, where letters are sorted by locality.
5. The local area postman carries the letter in his bag and delivers it straight into Ahmed's hands at his home.

Postal Items:
1. Postcard (cheapest, open card for short messages)
2. Inland Letter Card (blue folded confidential letter)
3. Stamped Envelope (sealed cover for sending private letters and documents).

Evolution of Communication:
• Old handwritten letters took 4 to 7 days to travel across the country by road and rail.
• Today, smartphones allow instantaneous communication via video calls, WhatsApp text messages, and emails that reach anywhere on Earth within a single second.

Postal Stamp Role:
• A postage stamp proves that the sender has paid the fee for postal transportation.
• If you post an envelope without a stamp, the postal service marks it 'Bearing', and the receiver has to pay double the postage charge before receiving the letter.

Observations:
Animals move in diverse ways adapted to their bodies:
• Birds (Crow, Pigeon): Fly using wings and hop on two feet.
• Mammals (Cow, Dog): Walk and run on four legs.
• Reptiles (Lizard, Snake): Crawl on walls or slither on the ground.
• Insects (Ant, Grasshopper): Walk on six legs and hop/fly.

Habitats:
• (a) On trees: Monkey, Squirrel, Owl.
• (b) In water: Fish, Frog, Crocodile.
• (c) On land: Horse, Elephant, Goat.
• (d) In burrows: Rabbit, Earthworm, Snake.

Five Senses:
1. Eyes: Help us see shapes, colours, and identify hazards.
2. Ears: Help us hear traffic horns, spoken words, and alarm sounds.
3. Nose: Helps us smell food, flowers, and detect smoke or gas leaks.
4. Tongue: Helps us taste sweet, sour, salty, and bitter food.
5. Skin: Helps us feel touch, heat, cold, roughness, and pain.

Rain and Plant Health:
• Rain comes from water evaporating from rivers, ponds, and seas, forming clouds in the sky that cool and condense into rain droplets.
• Rain washes off thick dust accumulated on leaves, unblocks stomata for breathing, and deeply soaks the roots with fresh mineral-rich moisture.

Regional Food Factors:
• What people eat depends directly on what grows easily and abundantly in their climate and geography.
• Kerala has coastal climate, abundant rainfall, and coconut groves, making fish and rice staples.
• Punjab has fertile plains ideal for wheat and mustard cultivation, and a strong dairy culture.

Matching:
• (a) Idli — (2) Steaming
• (b) Puri — (1) Frying in oil
• (c) Roti — (3) Roasting on Tawa.

Stilt Houses:
• Bamboo Stilts: Keep the house 10 to 12 feet above ground level to prevent floodwaters and wild animals from entering.
• Sloping Roofs: Allow torrential rainwater to slide off quickly without accumulating or causing leaks.

Community Helpers:
• (a) Mends shoes: Cobbler
• (b) Delivers letters: Postman / Mail carrier
• (c) Shapes clay pots: Potter
• (d) Treats sick people: Doctor.

Web of Life & Food Chain:
• The Web of Life shows that every living organism is interconnected and depends on others for survival.
• Food Chain: Sunlight → Grass (Producer) → Deer (Herbivore) → Lion (Carnivore).
If grass disappears, deer starve; if deer disappear, lions cannot survive.

Answers:
• (a) True: Braille uses raised dots felt with fingertips.
• (b) True: Rain replenishes rivers, lakes, and groundwater.
• (c) False: Animals communicate through warning calls, scents, and body language to alert their group of predators.