ননীর পুতুল = অল্প শ্রমে কাতর 

যে সকল পরিমাপযোগ্য ভৌত রাশিকে সম্পূর্ণরূপে প্রকাশ করবার জন্য মান ও দিক উভয়েরই প্রয়োজন হয় তাদেরকে সদিক রাশি বা দিক রাশি বা ভেক্টর রাশি বলা হয়। যেমন— সরণ, ওজন, বেগ, ত্বরণ, বল, তড়িৎ প্রাবল্য ইত্যাদি হল ভেক্টর রাশি।

কল্যাণী নেমেছিল- কানপুর স্টেশনে

The Organisation for Economic Co-operation and Development is an intergovernmental organisation with 38 member countries,founded in 1961 to stimulate economic progress and world trade. It is a forum whose member countries describe themselves as committed to democracy and the market economy, providing a platform to compare policy experiences, seek answers to common problems, identify good practices, and coordinate domestic and international policies of its members.

Member countries

Current members

As of May 2021 there are 38 members of the OECD:

Country	Application	Negotiations	Invitation	Membership	Geographic location	Notes
Australia				7 June 1971	Oceania
Austria				29 September 1961	Europe	OEEC member
Belgium				13 September 1961	Europe	OEEC member
Canada				10 April 1961	North America
Chile	November 2003	16 May 2007	15 December 2009	7 May 2010	South America
Colombia	24 January 2011	30 May 2013	25 May 2018	28 April 2020	South America
Costa Rica	9 April 2015		15 May 2020	25 May 2021	Central America	Joined OECD in 2021
Czech Republic	January 1994	8 June 1994	24 November 1995	21 December 1995	Europe
Denmark				30 May 1961	Europe	OEEC member
Estonia		16 May 2007	10 May 2010	9 December 2010	Europe
Finland				28 January 1969	Europe
France				7 August 1961	Europe	OEEC member
Germany				27 September 1961	Europe	Joined OEEC in 1949 (West Germany).Previously represented by the Trizone.
Greece				27 September 1961	Europe	OEEC member
Hungary	December 1993	8 June 1994		7 May 1996	Europe
Iceland				5 June 1961	Europe	OEEC member
Ireland				17 August 1961	Europe	OEEC member
Israel	15 March 2004	16 May 2007	10 May 2010	7 September 2010	Middle East
Italy				29 March 1962	Europe	OEEC member
Japan	November 1962		July 1963	28 April 1964	Asia
Latvia		29 May 2013	11 May 2016	1 July 2016	Europe
Lithuania		9 April 2015	31 May 2018	5 July 2018	Europe
Luxembourg				7 December 1961	Europe	OEEC member
Mexico			14 April 1994	18 May 1994	North America	Joined OECD in 1994
Netherlands				13 November 1961	Europe	OEEC member
New Zealand				29 May 1973	Oceania
Norway				4 July 1961	Europe	OEEC member
Poland	1 February 1994	8 June 1994	11 July 1996	22 November 1996	Europe
Portugal				4 August 1961	Europe	OEEC member
Slovakia	February 1994	8 June 1994	July 2000	14 December 2000	Europe
Slovenia	March 1996	16 May 2007	10 May 2010	21 July 2010	Europe
South Korea	29 March 1995		25 October 1996	12 December 1996	Asia	Officially the Republic of Korea
Spain				3 August 1961	Europe	Joined OEEC in 1958
Sweden				28 September 1961	Europe	OEEC member
Switzerland				28 September 1961	Europe	OEEC member
Turkey				2 August 1961	Middle East	OEEC member
United Kingdom				2 May 1961	Europe	OEEC member
United States				12 April 1961	North America

Source: Wikipedia  

নাপাম বোমা এজটি জেলিং এজেন্ট এবং উদ্বায়ী প্রেট্রোকেমিকেলের একটি অন্তর্নিবিষ্ট মিশ্রণ। নামটি মূল পুরুত্ব এবং জেলিং এজেন্টগুলির দুটি উপাদান একটি পোর্টম্যানট্যু: নেফথেনিক এসিড এবং প্যালমিটিক এসিডের সহ অনুপযুক্ত অ্যালুমিনিয়াম লবণ। নাপাম বোমা মানুষের ক্ষতি করে কিন্তু দালান ঘরবাড়ি ক্ষতি হয়না।

আমরা জানি $$\begin{gathered} (a-b{)}^2=(a +\; b{)}^2 -4ab \\ \Rightarrow (a-b{)}^2=4-4 \\ ab=1 .....(2) \\ .\text{'}. a-b=0 .......(3) \\ (1) +\; (3) করে পাই , 2a =2, \Rightarrow a=1 \\ (1) -(3) করে পাই , 2b =2, \Rightarrow b=1 \end{gathered}$$

মনে করি, আসল = ক টাকা
. '. মুনাফা আসল = ( ২*ক) = ২ক টাকা।
. '. মুনাফা = (২ক - ক) = ক টাকা
আবার, মুনাফা আসল = (৩*ক) = ৩ক টাকা।
. '. মুনাফা = (৩ক - ক) = ২ ক টাকা।
এখন, ক টাকা মুনাফা হয় = ৬ বছরে
. '. ১ টাকা মুনাফা হয় = ৬/ক
. '. ২ক টাকা মুনাফা হয় = ৬*২ক/ক = ১২ বছর।

Prepositions are used to link nouns, phrases or pronouns to other words in a sentence. They are used to indicate the location of the nouns and pronouns.

Complete answer:
Congratulating means to praise or compliment someone for their achievements.
As given in the hint, prepositions modify the given noun or pronoun in a sentence.
Example- He swam across the pool. Here, the preposition ‘across’ modifies the position of the noun ‘he’.
In the given question: X is congratulating Y on his success. So, here ‘I’ is the subject and ‘you’ is the object.
Hence, the correct answer is- I congratulate you on your success. We have used the preposition ‘on’ to indicate an occasion or a subject.
Now, let’s look at the given options-
- Of- It is used to denote the relationship between two things. Hence, it is an incorrect option.
- With- It is generally used with feelings and emotions. Hence, it is an incorrect option.
- By- It is used to show the position of the noun in the sentence. Hence, it is an incorrect option.
- On- It is used to indicate an occasion or a subject. Hence, it is the correct option.

> The correct answer is Option ‘d’.

Note: ‘On’ is commonly used in locative context as it indicates the position of an object. But it can also be used to indicate occasions and subjects.