Question

I ...... by six o'clock 1) worked 2)work 3)had already worked 4) already had worked

Answer 1

i worked by six o'clock.

Answer 2

I WORKED by six o’clock.
Ответ: 1.
здесь нужно прошедшее время, те просто окончание -ED

Answer 3

The correct answer is: 3) had already worked