Question

We shall be back ......... 4 O' clock. Preposition

Answer 1

we shall be back at 4 O'clock.
.....is the answer.....

Answer 2

ANSWER:

     We shall be back by 4 O'clock.  

EXPLANATION:

   The preposition used in the above sentence is ‘by’. Prepositions are words that show the relation between the noun and pronouns or show the link between other words such as nouns, pronouns and phrases.

  Here the word ‘by’ means ‘around, before a particular time or not later than’ in terms of time. In the sentence “We shall be back ‘by’ 4 O’clock” is to tell that they will be they will be back no later than 4 or around 4.