There are various types of fever. Dengue is one of them. It (a)___ by biting of mosquito (b)___ Aedes. It (c)___  serious health hazard. Vomiting, high temperature, blood platelets etc. make the patient tormented. Many patients (d)___ if blood platelets (e)___ below 50, Much care and proper treatment (f)___ to save dengue affected patients. In order to (g)___ourselves free from dengue, we (h)___ our environment clean. Living place of Aedes larva should (i)___ with a view to (j)___ ourselves aloof from mosquito bite the use of curtain is essential.

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.