Question

the old woman _________ her socks ( darn )​

Answer 1

Answer:

The old woman 'darned' her sock

Answer 2

Answer:

The old woman was darning her socks.

'darn' is a verb that means 'to repair a hole in a piece of clothing by sewing stitches across the hole'.

Explanation:

Since the tense is not specified, we may use any tense to fill the blank. Here the blank has been filled using past continuous tense.

We use the past continuous for an action that we were in the middle of. We often use the past continuous and simple past together when one (shorter) action comes in the middle of another (longer) one.  

Past continuous is also used to talk about actions that happen temporarily in the past.  

I was reading a book.

The birds were chirping in the garden.

The following verb/s form is used to express past continuous tense:

Was/were+V1+-ing