Here, the correct verb is "could".

Explanation: We use 'wish' to talk about something that we would like to be different in the present or the future. It's used for things which are impossible or very unlikely. We also use 'wish' with 'could' to talk about things in the present or future that we would like to be different. In this situation, 'could' is the past simple of 'can'. See below example:

I wish I could correct the mistakes that I've made.

'Defalcate’ means embezzle (funds with which one has been entrusted).

‘Devastate’ means to destroy or ruin.

‘Devour’ means to eat hungrily or quickly.

‘Embezzle’ means to steal or misappropriate
Although, the verbs "defalcate" and "embezzle" have the same meaning, it is more appropriate to use the simple verb "embezzle" as the verb "defalcate" also means the same.

‘Sunk’ is the past participle of ‘sink’ which means to go down below the surface of something, especially of a liquid; become submerged.

‘Showered’ means to fall or be thrown in a shower.

‘Stuck’ means unable to move, or set in a particular position, place, or way of thinking.

‘Battered’ means injured by repeated blows or punishment.

The sentence is written in an idiomatic way. It means to say that rain has overflowed Mumbai and the city is ‘sunk’ in the water because of it. So, the correct word is "sunk".

"Connected" is a verb; so it will be followed by an adverb. Options B and D have adjectives which cannot be used in the sentence. Option A is an adverb; however, it does not give any meaning to the sentence. The correct adverb is "respectably".

"Without fail" is a phrase which means certain with no exception; always. Thus, option C is the correct answer.

The correct words to be used in the blank field are "any different". Any is a determiner and a pronoun. Any is mostly used for indefinite quantities in questions and negative sentences. Since, the given sentence is negative and "different" is an adjective, so the use of "any" is correct in the sentence.

Let's understand the meaning of each phrasal verb given in the options. This will help us to find out the correct phrasal verb which fits best according to the meaning of the sentence:

Fall in = take one's place in a military formation

Fall out = to have an argument

Fall off = a decrease in something

Fall on = attack fiercely or unexpectedly

As the sentence is about squadron leader ordering his men, the correct phrasal verb is "fall in".

The correct pronoun to be used in the sentence is "his". Here, the verb "accepting" is a gerund and working as a noun. With a noun or gerund, a possessive pronoun is used always. See some examples:

I don't like your coming late to the office.
He insisted on my staying in the hostel.

Let's understand the meanings of different phrasal verb formed by the verb "turn":

Turn in = 1 : to make an entrance by turning from a road or path. 2 : to go to bed in the evening

Turn out = prove to be the case

Turn down = to refuse to think about, believe or accept something

Turn up = to appear, arrive or attend

The sentence gives correct meaning when we use the phrasal verb "turn up". So, option D is the correct answer.

One cannot see clearly in low or dim light. Therefore, the adjective "scarcely" is the correct filler for the sentence. It means only just; almost not.