From the words or group of words lettered A to D, choose the word or group of words that best completes each of the following sentences. By the time they ar...

Answer Details

The word or group of words that best completes the sentence is "shall have finished". This is because the sentence talks about an action that will be completed in the future before a certain time, and the future perfect tense is used to express this. "Shall have finished" is the correct form of the future perfect tense for the pronoun "we". The other options, "could have finished", "will finish", and "have finished", are not correct in this context. "Could have finished" is the past conditional tense and is not appropriate for a future event. "Will finish" is the simple future tense and does not express the completion of the work before a certain time. "Have finished" is the present perfect tense and does not express a future event.