Explanation

She sings a song, does not is she here doesn't she is " Tag question"

A tag question is a statement + mini-question.

Sentences with action verbs in the simple present tense form a question tag using the verb 'do/does' and its corresponding negative form. 

Explanation

Last month shows past tense.

Second form (threw) is used in simple sentence of Past Indefinite Tense,

Explanation

Keep is a verb which means to maintain.

Kept is the second and third form of Keep.

The subject 'One' has to be replaced with 'One's promises' keeping the tense same.

Active voice: One must keep one's promises.

Passive voice: One's promises must be kept

Explanation

Actually, the most appropriate answer would be ' object to his being taken on'...

Possessive adjective instead of complement pronoun 

Explanation

The word 'for' is used to show a period of time, be it in the past, present or future.

Explanation

The sentence is in Simple Present Tense.

 The model (can) has been used in active which changed to can be in passive.

Explanation

This is a sentence of Present Perfect Continuous Tense.

Formula: Subject + has/have + been + verb + ing + object

Explanation

 We should not encourage Indiscipline because "should" has not been mentioned in option A, B & C.

Note:- It may be noted that more valuable details about this question shall be upload here very soon.

Explanation

"Given up" means to quit or stop doing something, which fits the context of quitting smoking based on advice. 

Explanation

Next week indicates future and we use will for future tense.

Have come indicates present tense while had come indicates past.