II.
         Facebook says it is developing a device that would permit users to use their hand tocontrol virtual objects. The device, worn on the wrist, is designed to work with glasses tocreate an augmented reality, or AR, experience. Facebook recently described its device in areport on its website. The social media service said the technology would permit users toenter virtual worlds,   16    they could control different objects simply with fingermovements. The AR system is expected to “transform the way we   17    people near andfar” in the future, Facebook said.
         In the past, Facebook has mostly centered its AR development on improving gamingexperiences. Now, it is aiming to expand the technology to be used in more everyday ways.   18    this goal in mind, Facebook said one of the most important considerations was tofind the right kind of device to control the AR glasses. It would have to be easy to use,wearable, always available and powerful enough to perform complex actions. The companydecided a wristband would be the best choice.
         The device will use a technology known as electromyography, or EMG, to translatecomplex hand movements. EMG measures electrical activity in muscles when they move.Sensors will “translate electrical motor nerve signals that travel through the wrist to the handinto digital commands that you can   19     the functions of a device,” Facebook said.
         These signals -- which start in the brain and travel through the wrist -- are so clear thatEMG can understand finger movements 20 one millimeter, the company said. It addedthat in the future, “it may even be possible to sense just the intention to move a finger.”
【題組】16.
(A) why
(B) where
(C) when
(D) that