The correct sentence is:

The place was not only cold but also damp.

Explanation: In this sentence, the use of "only" and "also" is redundant. Instead, "not only...but also" is the correct correlative conjunction to use. Also, the conjunction "and" should be replaced with "but" for proper contrast between the coldness and dampness of the place.

The correct sentence is:

Many a person is unable to distinguish right from wrong.

Explanation: "Many a person" is a singular phrase and should be followed by a singular verb, which is "is" in this case. Additionally, the preposition "of" should be replaced with "to," and the article "the" is needed before the noun "right."

The correct sentence is:

We are coping with the problems to the best of our ability.

Explanation: The verb "coping" should be followed by the preposition "with," and the definite article "the" is necessary before the noun "problems." Additionally, the phrase "to the best of our ability" is a common idiomatic expression used to indicate doing something as well as one can.

The underlined segment in the given sentence does not need improvement. It is already grammatically correct and conveys the intended meaning effectively:

Explanation: The verb "has" is the correct form to use with the pronoun "she." The original sentence, "She are having," is grammatically incorrect.

The correct answer is under suspicion. Key Points. The idiom "Under a cloud" means one is under suspicion of doing something fishy. Hence the correct option for the idiom "under a cloud" is "under suspicion".

The correct answer is 'went to bed'. To Hit the sack means to go to bed. After the long journey, he hit the sack as soon as he reached home.

The most appropriate meaning of the given idiom "In queer street" is "In debt." In queer street: in trouble, usually because of debt. Example: He will be in the queer street if he continues buying expensive things.