English is a language shared by several diverse cultures, each of ____ uses it somewhat differently.
The professor gave orders that the test ___________before 5:30.
The possibility of a way out of the impasse(僵局) had never ____________ to anyone.
I appreciated ____ the opportunity to study abroad two years ago.
_______, I’d have told you.
20. He reads newspapers every day to keep himself_______about what's going on in the world.