英和和英

an opportunity opened up

open wide

freedom of choice

The selection was narrowed

The curtain rises

The plays begins

The performance commences.

optional choice―free choice

of a person's characteristic, being frank

to disclose

open

a possible alternative

to open the curtain―raise the curtain―draw （back） the curtain

in an open way

to open again after closing

to hold a meeting

to go from one tack to the other

a window of opportunity

a natural opening in something

to start a ceremony

to extract the square root （of a number）

to make a thing open

open invitation

to open (something) completely

to open completely

free choice―optional choice

to open widely

an arbitrary choice

something to be opened

a possibility