Question

Present Perfect Tense
workers ________ day and night
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Answer 1

Workers had been working day and night.

Answer 2

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$\rightarrowtail$ Workers have worked day and night.

$\:$

$\red{\boxed{\mathfrak\colorbox{grey}{Knowledge \: Cell}}}$

The present perfect tense refers to an action or state that either occurred at an indefinite time in the past (e.g., we have talked before) or began in the past and continued to the present time (e.g., he has grown impatient over the last hour). This tense is formed by have/has + the past participle.