draw a blank
To be unable to recall a required piece of information.
I should know that person's name, but I'm drawing a blank.
VERBS
be
go
My mind went blank during the exam and I couldn't remember anything.
remain
leave sth
She left several questions blank because she didn't know the answers.
ADV
completely, entirely
VERBS
be, look
When I asked him about the missing keys, his expression went completely blank.
go
During the exam, I suddenly went blank and couldn't remember any of the answers.
remain
ADV
completely
studiously
She stared studiously blank during the meeting, refusing to reveal her true feelings about the proposal.
VERB + BLANK
fill in
Please fill in the blank with your name before you submit the form.
leave
When you finish the test, try to leave as few blanks as possible.
VERB + BLANK
fire
The police officer fired blanks during the training exercise to simulate a real emergency situation.