The rational numbers includes all positive numbers, negative numbers and zero that can be written as a ratio (fraction) of one number over another. Whole numbers, integers, fractions, terminating decimals and repeating decimals are all rational numbers. Any rational number is trivially also an algebraic number. Examples of rational numbers include. , 0, 1, 1/2, 22/7, 12345/67, and so on. Farey sequences provide a way of systematically enumerating all rational numbers. Rational numbers include natural numbers, whole numbers, and integers. They can all be written as fractions. Sixteen is natural, whole, and an integer. Since it can also be written as the ratio 16:1 or the fraction 16/1, it is also a rational number.

The British set up record rooms to preserve all important documents and letters. The record rooms were attached to all administrative institutions. All the administrative offices, the village tahsildar’s office, the collectorate, the commissioner’s office, the provincial secretariats and the law courts had record rooms attached to their offices. The British also set up specialised institutions like archives and museums to preserve important records. In the early nineteenth century, these documents were carefully copied out and beautifully written by calligraphists. By the middle of the nineteenth century and with the spread of printing, several copies of these records were printed as proceedings of each government department

Raja Ram Mohan Roy was a great social and religious reformer. He undertook several social reforms to change the society and worked to uplift the status of women in India. He started the Brahmo Samaj. The Brahmo Samaj believed in the worship of one God. Raja Ram Mohan Roy advocated Western learnings and Sciences. 
He was against the caste system. He worked emphatically for improving the condition of women in the Indian society. It was largely due to his efforts that the practise of 'Sati' was made a crime punishable by law. He criticised the 'purdah system', polygamy, discouraged child marriages and advocated the rights of widows to remarry.
It was because of the efforts made by him to eradicate the social evils in the society, that Raja Ram Mohan Roy is known as 'Father of the Indian Renaissance'. 

It is the use of microorganisms to help decompose pollutants.

Undesirable plants that grow naturally along with the crop are known as weeds. It can be controlled by the process of weeding. Weeding involves the removal of unwanted and uncultivated plants called weeds.

Examples commonly are plants unwanted in human-controlled settings, such as farm fields, gardens, lawns, and parks.

Which does he think is natural, to love or to hate?

Answer: Mandela thinks for human beings it is natural to love rather than to hate.

Large deposits of iron ore are also found in India and China. Brazil produces high grade iron ore and is its largest producer in the world. India is the leading producer of mica in the world. India is also one of the leading producers and exporters of salt.

The past continuous is formed from the past tense of "to be" with the base of the main verb plus the ending "-ing" form of the verb. One example of this tense is: I was watching television when she called me last night.  Past Continuous Tense. Subject + Was/Were + Verb (Ist form) + Ing + Object + (.) In Past Continuous Tense 'Was / Were' is used in sentence and 'Ing' is added with first form of the main verb. 

Past Continuous Tense

• The sun was shining every day that summer.
• As I spoke, the children were laughing at my cleverness.
• The audience was applauding until he fell off the stage.
• I was making dinner when she arrived.
• At 6 o'clock, I was eating dinner.
• She was talking constantly in class in those days.
• At noon, he was arriving.

Animals are classified based on their characteristics. They are eminent from algae, plants, and fungus where rigid cell walls are absent. Some are also heterotrophic, in general, they digest their food within the internal chambers which again distinguish them from algae and plants. Another elite character of these species is that they are motile, except in certain life stages.

Question: 3/7 + (- 6/11) + (- 8/21) + (5/22)
Answer:
Taking L.C.M. of the denominators 7, 11, 21 and 22 and then solving it.

L.C.M. of 7, 11, 21 and 22 = 2*3*7*11
= 462
            
= (462/7)*3 - (462/11)*6 - (462/21)*8 + (462/22)*5

= (198/462) - (252/462) - (176/462) + (105/462)

= (303/462) - (428/462)

= (-125/462)

When a solution of magnesium salts is combined with alkaline water it instigates precipitation of solid magnesium hydroxide. The reaction is as follows:

Mg²⁺ + 2 OH⁻ → Mg(OH)₂

Commercially it is produced by treating lime and sea water. Approximately one ton of magnesium hydroxide is obtained from 600 m³ of seawater. Calcium hydroxide is more soluble in magnesium hydroxide therefore Mg(OH)₂ precipitates as a solid. The reaction is as follows:

MgO + H2O → Mg(OH)₂

Monkombu Sambasivan Swaminathan is a well-known Indian agricultural scientist. 

Dr. MS Swaminathan is known as the Father Of India's Green Revolution