Some day, our world may ____ (fill) with driverless cars. But.____will we communicate with them if there's nobody in the driver's seat?

    At present, drivers can make gestures like____ (nod) when they let us cross the street.____ self-driving cars don't have this ability.

    The US car maker Ford and its partner Virginia Tech ____ (try) to solve this problem. The team is testing a method ____uses light signals. For example, a slow-blinking tight shows the car is coming to  ____stop, and a rapidly flashing light   tells passers-by that the car is about to speed up.

    ____ (test) the method on real roads, the team has designed a special suit that looks like a car scat. When a driver wears it, it appears as if the car were driverless.

    The team has ____ (successful) collected more than 1,500 hours of data, which has recorded how people interacted with a “driverless” car. Ford says it plans to share the data ____ 11 other car makers, which should lead to a signaling system that will be used in every driverless car.