6 . 听下面一段独白，回答以下小题。

Baby Steps Toward Autonomy…

Companies, like Google and Tesla, didn't even exist when Toyota introduced the Prius in1997. However, they have become major     1     in the auto industry recently. Both of them aim to introduce fully autonomous cars ---that is, cars that drive themselves---within the next several years.

Self-driving cars are expected to be much safer than human-driven ones. But even if the first robot cars     2     the roads in the next few years, most of us probably won't give up driving entirely for at least another 15 or 20 years. In the meantime,     3     cars will gradually take over certain aspects of driving.

Companies have been adding     4     features to cars since the 1990s---things like adaptive cruise control, which uses sensors to adjust a car's speed based on the traffic in front of it, and automated parallel parking. Some cars automatically stop—or at least slow down—if a driver doesn't step on the brake in time to avoid a crash. In a certain model developed in 2017, the driver will be able to change     5     simply by hitting the turn signal for two seconds (the car will take care of the rest). Within a few years, cars may be able to determine when an accident is likely and make     6    to the cabin---moving seats, closing windows , retracting the steering wheel.

Even better than preparing for a crash, of course, is     7    one. Some vehicles     8     warnings when they detect, through cameras and sensors, that a driver is getting sleepy. Future cars might take over for     9     drivers---or automatically pull to the side of the road and shut down. Biometrics(生物识别技术）could aid this process. If a car has sensors that can measure a driver's breath and heart rate, it could     10     into self-driving mode when a driver has a heart attack.