throw something open to somebody

Từ điển Oxford Advanced Learner 8th

ˌthrow sthˈopen (to sb) derived
1. to allow people to enter or visit a place where they could not go before
2. to allow people to discuss sth, take part in a competition, etc
•The debate will be thrown open to the audience.
•The organizers are throwing the contest open to under 21s for the first time.
Main entry: ↑throw_derived