单选题A personal alarm is designed for old people to _____.A detect safety conditions at homeB avoid falls in the bathroomC send out signals for helpD make phone calls easily

共用题干
第二篇

A Phone That Knows You're Busy

It's a modern problem : you're too busy to be disturbed by incessant（连续不断的）
phone calls so you turn your cellphone off.But if you don't remember to turn it back on
when you're less busy,you could miss some important calls.If only the phone knew when
it was wise to interrupt you,you wouldn't have to turn it off at all.Instead,it could let calls
through when you are not too busy.
A bunch of behavior sensors（传感器）and a clever piece of software could do just
that,by analyzing your behavior to determine if it's a good time to interrupt you.If built into
a phone,the system may decide you're too busy and ask the caller to leave a message or
ring back later.
James Fogarty and Scott Hudson at Camegie Mellon University in Pennsylvania based
their system on tiny microphones,cameras and touch sensors that reveal body language
and activity.First they had to study different behaviors to find out which ones strongly
predict whether your mind is interrupted.
The potential"busyness"signals they focused on included whether the office doors
were left open or closed,the time of day,if other people were with the person in question,
how close they were to each other,and whether or not the computer was in use.
The sensors monitored these and many other factors while four subjects were at work.
At random intervals,the subjects rated how interruptible they were on a scale ranging from
"highly interruptible"to"highly not-interruptible".Their ratings were then correlated with
the various behaviors. " It is a shotgun（随意的）approach: we used all the indicators we
could think of and then let statistics find out which were important,"says Hudson.
The model showed that using the keyboard,and talking on a landline or to someone
else in the office correlated most strongly with how interruptible the subjects judged
themselves to be.
Interestingly,the computer was actually better than people at predicting when someone
was too busy to be interrupted.The computer got it right 82 percent of the time,humans 77
percent.Fogarty speculates that this might be because people doing the interrupting are
inevitably biased towards delivering their message,whereas computers don't care.
The first application for Hudson and Fogarty's system is likely to be in an instant
messaging system,followed by office phones and cellphones. "There is no technological
roadblock（障碍）to it being deployed in a couple of years,"says Hudson.

A big problem facing people today is that
A:they must tolerate phone disturbances or miss important calls.
B:they must turn off their phones to keep their homes quiet.
C:they have to switch from a desktop phone to a cellphone.
D:they are too busy to make phone calls.