I want to test the ability of students to read a passage and answer questions about it. Could you please come up with a good question for the passage "It has been possible to teach a migration route to a flock of birds, for example in re-introduction schemes. After a trial with Canada geese Branta canadensis, microlight aircraft were used in the US to teach safe migration routes to reintroduced whooping cranes Grus americana."? 

Microlight aircraft were used in the U.S. and where?