If you don’t know the answer to something, you say: “______”
ORBIS doctors invite local doctors and nurses _____ to learn new skills.
We didn’t go to the concert because we couldn’t to buy the tickets to it.
English is used an official language in more than 70 countries.
helps build a better world for everyone, especially children around the world.
—People have realized how important the environment is, but still trees ____in the world every year.— We must do something to stop it.