Choose the word(s) or phrase(s) which best fill(s) the gap. By the time the plane reaches Harare, it __________in the air for twelve hours
- has been
- would be
-
would have been
- should be
The correct answer is: C
Explanation
'By the time' is an adverb of time that can be used in the present, past and future tense. The question is, however, in the present tense which will be needing a present perfect tense to complete the sentence.
There is an explanation video available .