阅读理解：
A Phone That Knows Youre Busy
Its a modern problem：youre too busy to be disturbed by incessantphone calls so you turn your cellphone off .But if you dont remember to turn it back on when youre less busy.you could miss some important calls if only the phone knew when it was wise to interrupt you，you wouldnt have to turn it off at all. Instead，it could let calls through when you are not too busy
James Fogarty and Scott Hudson at Camegie Mellon University in Pennsylvania based their system oil tiny microphones，cameras and touch sensors that reveal body language and activity. First they had to study different behaviors to find out which ones stongly predict whether your mind is interrupted
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 fromhighly interruptibletohighly not-interruptible . Their ratings were then correlated with the various behaviors . It is a shotgunapproach：we used all the indicators we could think of and then let statistics find out which were important， says Hudson
Interestingly，the computer was actually better than people at predicting when someone was too busy to be interrupted . The computer got it right 82 per cent of the time，humans 77 per cent. Fogarty speculates that this might be because people doing the interrupting are inevitably biased towards delivering their message，whereas computers dont care.
36 A big problem facing people today is that
B they must turn off their phones to keep their homes quiet.
D they are too busy to make phone calls.
A could help store messages.
C could tell when it is wise to interrupt you.
38 Scientists at Carnegie Menon University tried to find out
B when it was a good time to turn off the computer.
D which behaviors could tell whether a person was busy