The correct option to complete the sentence is "is".

Key Points

• In English, fractions and percentages are usually singular when they refer to a quantity considered as a whole.
• In this case, "two-thirds of the city" is considered as one entity, one quantity.
• Therefore, we use "is" (singular form of "be").
• So the sentence would be: "Two-thirds of the city is in ruins."
• Hence, the correct answer is option 1.

Additional Information

• Now let's take a look at the other options:
  • "are": This would be used if "two-thirds of the city" were being considered as separate entities. For example, if we were talking about two-thirds of the city's buildings, we might say "Two-thirds of the city's buildings are in ruins." In that case, we're considering each building separately.
  • "were": This is the past tense of "are". You would use this if you were talking about the city being in ruins in the past. For example, "Two-thirds of the city were in ruins after the earthquake, but most of the buildings have been rebuilt now."
  • "have": This is the present perfect form of "have". It is used to talk about actions or states that started in the past and continue to the present. It doesn't fit in this sentence because "in ruins" is not an action that can continue to the present.

The correct answer is: Our school principal declared that the new rule was applicable to everyone.

Key Points

• School: This is a noun referring to the educational institution, and it is spelt correctly.
• Principal: This is a noun, referring to the head of the school, and it is spelt correctly.
• Declared: This is a verb, past tense, and it is spelt correctly.
• Applicable: This is an adjective describing the rule, and it is spelt correctly.
• Everyone: This is a pronoun, and it is spelt correctly.

So, it is clear that every word in the sentence is spelt correctly, and the sentence is grammatically sound. It effectively conveys the message that the school principal declared a new rule that applies to everyone.

Thus, option 1 is the correct answer.

The correct answer is "A"

Key Points

• There is an error in part (a). The correct phrase should be: "I was going to"
• The verb "had going" should be replaced with the verb "was going" because "was going" is the past continuous form of the verb "go," which describes an action that was in progress at a specific time in the past.
• The verb "go" means "to travel or move to a place," and it is used to describe the action of moving from one place to another.
• In this case, the speaker was in the process of going to the library at a specific time in the past in order to return some books, so the past continuous form is appropriate.
• The past simple form, "had gone," describes an action that was completed in the past and has no connection to the present, which does not fit the meaning of the sentence in this context.

Thus, option 2 is the correct answer.

Correct sentence: I was going to the library to return some books. 

Here, the correct part is "to an range of health problems."

Key Points

• The error lies in the part "to an range of health problems."
• The incorrect use of the article "an" before the word "range" is incorrect.
• The word "range" starts with a consonant sound, so we must use "a" before "range."
• The correct answer is Option 4.

Correct sentence: A lot of adulterants are chemicals that can lead to a range of health problems in both children and adults.

The correct answer is Option 3 i.e. "Affluent".

Key Points

• Destitute: (निर्धन) - Lacking the basic necessities of life; extremely poor.
  • Example: After losing his job, he became destitute and lived on the streets.
• Affluent: (धनी) - Having a great deal of money; wealthy.
  • Example: She comes from an affluent family and has never worried about money.

Therefore, the correct answer is "Affluent".

Additional Information

• Glorious: (शानदार) - Deserving great admiration, praise, and honor.
  • Example: The athletes returned home to a glorious welcome.
• Disturbed: (परेशान) - Showing signs of mental illness or distress.
  • Example: He had been acting disturbed and erratic lately.
• Ridiculous: (हास्यास्पद) - Deserving or inviting mockery or derision; absurd.
  • Example: It's ridiculous to expect perfection.

The correct answer is 'Option 3'.

Key Points

• The correct option is: 'See eye to eye'
• Explanation: The idiom "see eye to eye" means to agree on a subject or see things the same way.
• It is the best fit for the bracketed text "(share the same opinion)" in the context of the sentence.

Therefore, the correct sentence is: 'His mother and I see eye to eye about his decision to drop out of college.'

Additional Information

• Leave no stone unturned: This idiom means to do everything possible to find something or to solve a problem, which doesn't fit the context.
• Paint the town red: This idiom means to go out and enjoy oneself flamboyantly, often involving drinking and dancing. It has nothing to do with sharing the same opinion.
• Feel blue: This idiom means to feel sad or depressed, which is not applicable in this context.

The correct answer is 'decided'.

Key Points

• The title of the given passage is 'A tit for tat'.
• The most appropriate word for the given blank is 'decided'.
• The given passage is in the past tense so the verb must be used in its past form(V2). 
• Thus, the correct answer is Option 3.

Correct Passage: The camel and the fox were very good friends and very good thieves. One day, the two friends decided to cross the river so that they could travel to a (2) ______ farm to steal food. The small fox (3) ______ swim, so the camel said to his friend, ‘Climb (4) ______ onto my back and I will swim across the (5)______.’

The correct answer is 'nearby'.

Key Points

• The title of the given passage is 'A tit for tat'.
• The most appropriate word for the given blank is 'nearby'.
• ‘Nearby’ means not far away in distance.
• The given passage states that the two friends decided to cross the river so that they could travel to a nearby farm to steal food.
• Thus, the correct answer is Option 4.

Correct Passage: The camel and the fox were very good friends and very good thieves. One day, the two friends decided to cross the river so that they could travel to a nearby farm to steal food. The small fox (3) ______ swim, so the camel said to his friend, ‘Climb (4) ______ onto my back and I will swim across the (5)______.’

The correct answer is 'could not'.

Key Points

• The title of the given passage is 'A tit for tat'.
• The most appropriate word for the given blank is 'could not'.
• ‘Could’ is used for saying that somebody had the ability to do something.
• The given passage states that the small fox could not swim.
• Thus, the correct answer is Option 4.

Correct Passage: The camel and the fox were very good friends and very good thieves. One day, the two friends decided to cross the river so that they could travel to a nearby farm to steal food. The small fox could not swim, so the camel said to his friend, ‘Climb (4) ______ onto my back and I will swim across the (5)______.’

The correct answer is 'up'.

Key Points

• The title of the given passage is 'A tit for tat'.
• The most appropriate word for the given blank is 'up'.
• In the given sentence 'climb up' is a phrasal verb. 
• It means 'to go up or ascend, especially by using the hands and feet or feet only (ऊपर जाना या चढ़ना, विशेष रूप से केवल हाथों और पैरों या पैरों का उपयोग करके)'.
  • Example: to climb up a ladder.
• Thus, the correct answer is Option 2.