हेलेन केलर प्रकृति की अनेक चीजों जैसे भोज-पत्र पेड़ की चिकनी छालं, चीड़ की खुरदरी छाल, टहनियों में नई, कलियों फूलों की पंखुड़ियों की बनावट को छूकर और सँघकर पहचान लेती है। जबकि इस नियामत से जिंदगी को खुशियों के इंद्रधनुषी रंगों से हरा-भरा किया जा सकता है'।

Use of plastics can be reduced by:
a. Make minimal use of plastic bags.
b. Use cloth or paper bag in place of plastics.
c. Educate the people about ill-effect of plastics

Our body adapts to low oxygen availability by increasing red blood cell production decreasing the binding capacity of haemoglobin and by increasing breathing rate.

The north East India gets the heaviest downpour while, the northwest part i. e in Rajasthan the rainfall is lower due to the aravali ranges which acts as a barrier

The male reproductive system consists of the following parts:

1. Testes: These are a pair of small-sized, oval-shaped, pinkish colored structures present in a thin-walled skin pouch called scrotal sac or *******. It protects the sperms against relatively high body temperature.
2. Epididymis: Epididymis is about 6 metres long highly coiled tube present on the superior pole of each testis.
3. Vasa deferentia (Seminal ducts): A vas deferens is a long, narrow tubular structure which starts from the tail of the epididymis
4. *****: It is a long cylindrical, erectile copulatory organ. It forms the external genitalia of males. The tip of the ***** is highly sensitive and is known as the glans *****.
   Accessory *** glands of male: These include a pair of seminal vesicles, a prostate gland and a pair of Cowper or bulbourethral glands. 
   The urethra also has mucus-secreting glands in its lining.
   Semen or seminal fluid: The secretion of accessory *** glands and mucus are added to sperms to form seminal fluid or semen.

• Sacred groves are the forests patches around the places of worship.
• Role in conservation:
  Sacred groves are held in high esteem by tribal communities as it forms part of their religious beliefs. Hence they do not allow cutting of even a single branch of a tree. This helps in the conservation of many endemic species (rare species) flourishing in that area.They are found in several parts of India e.g. Rajasthan (Aravalli hills), Madhya Pradesh (Sarjuja, Bastar), Meghalaya and Maharashtra. Several rare species of plants have been preserved over the generations in these areas

Yes, Hiawatha liked learning new language. Hiawatha called the birds 'chicken' and beasts 'brothers'

string function in Excel are as follows-

(1) len- len function in Excel helps you to to know the length of a string that is number of characters in a string.

(2)- MID( )- mid functions in Excel are used to extract the character from the middle of a string.

(3)-Left ( )- left function in Excel is used to extract the left character from a string.

Energy of photon (E) = {tex}\frac{\mathrm{hc}}{\lambda}{/tex}
h = 6.626 {tex}\times{/tex} 10^-34 Js, c= 3{tex}\times{/tex}10⁸ ms^-1, {tex}\lambda{/tex} = 4000 pm = 4000 {tex}\times{/tex} 10^-12 = 4 {tex}\times{/tex}10^-9 m
{tex}\therefore{/tex} Energy of photon (E) = {tex}\frac{\left(6.626 \times 10^{-34} \mathrm{Js}\right) \times\left(3 \times 10^{8} \mathrm{ms}^{-1}\right)}{\left(4 \times 10^{-9} \mathrm{m}\right)}{/tex}= 4.969 {tex}\times{/tex} 10^-17 J
Now, 4.969 {tex}\times{/tex} 10^-17 J is the energy of photon = 1
{tex}\therefore{/tex}1 J is the energy of photons = {tex}\frac{1}{4.969 \times 10^{-17}}{/tex}= 2.012 {tex}\times{/tex}10¹⁶ photons.

Basis of Classification is as follows:
- Level of Organisation
- Symmetry
- Layers of Cells
- Presence or Absence of Coelom
- Segmentation
- Presence or Absence of Notochord
Levels of Organisation
- Cellular Level. In some multicellular animals, the cell is responsible for all the metabolic activities in the animal body. This type of organization of function is termed as cellular level of organisation.
- Tissue Level. In certain animals cells performing the same function are arranged in a group. Example: Coelenterates.
- Organ Level. Some animals form specialized organs for specific functions.
Example: Platyhelminthes.
- Organ System Level. In higher and complex animals various organs group to form a complex organ system to perform specific function. Example:Molluscs, Chordata.

House is a place in which we live. All living being such as animals birds humans need a place to live. It keeps us safe from bad weather such as rain, sunlight, storm and other natural disasters. That's why we need a house. A house is a place where the family lives together all of us need a house to live in a house keeps us safe it protects us from heat. and rain it keeps us warm during the cold winter. it protects us from the wild. and dangerous animals parts of a house is made up of walls.