Complete the text adding suffixes, prefixes or the both with the root words given in the parentheses,

Public transportation in cities faces (a) _____ (efficient) due to traffic congestion. Commuters often experience (b) _____ (delay) journeys, leading to (c) ______ (frustrate). (d) ______ (implement) the modern systems like metro rails could provide (e) _____ (rely) services. However, (f) _____ (maintain) requires ongoing (g) _____ (invest). Passengers appreciate (h) ______ (comfort) rides without (i) _____ (overcrowd). Ultimately, (j) ______ (improve) infrastructure benefits everyone in urban areas.

We are not ungrateful to the freedom fighters.

Their contribution is the greatest thing. 

An imperative sentence expresses a command, request, advice, or suggestion. It typically starts with a base form of a verb, and the subject 'you' is often understood but not stated. To form a negative imperative, 'Do not' or 'Never' is placed at the beginning of the sentence.

In the given sentence, "You should never disrespect or forget our martyrs," 'should never' indicates a strong suggestion or advice against an action. To transform this into an imperative sentence, we remove the implied subject 'you' and the auxiliary 'should', directly starting with 'Never' to convey the strong negative command or advice.

Our government has built the national memorial with a view to paying tribute to their memories. 

 (e) A freedom fighter is greater than any other son of the soil.

Our independence was got/gotten by us for their sacrifice.