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las vegas (afp) — children may not like it but a british technology firm has invented an electronic babysitter -- a wristwatch-like device that lets parents know where their children are at all times.
the gps child locator, or num8, attaches securely to a child’s wrist and contains a global positioning system (gps), said matthe w salmon, a spokesman for the manufacturer, lok8u.
"it uses gps and gsm (global system for mobiles) technology with an accuracy of 10 feet (three meters)," he said. "it tracks your child."
"it only starts working when the device is connected to the child’s wrist," salmon said, and is "very difficult to get off."
"even if the child managed to get it off it would send an emergency text message through to your mobile phone," he said. "it would give you a google maps image with their exact location, the street name and the zip code."
when a child is wearing the device, a parent sends the text message "wru" and the chi ld’s current location is sent back to a mobile phone or computer.
parents can also log on to the company website to discover their child’s present location.
"you can also set up a perimeter, an invisible fence, and if they wander out of this invisible fence which you put on the internet it will warn you," salmon said. "it will text you immediately."
salmon said the device is waterproof and shockproof and lasts for three days with a full charge.
it will be available in both britain and the united states this year and retails for 200 dollars with a 10 dollar a month subscription fee.
he said the company had received thousands of inquiries about the device since launching it this week. "fifty percent are positive, 50 percent are negative, that it’s a bit big brotherish," he said. "but it’s really just about letting you have *** of mind."
小题1:only when does the device begin to work.

a．it uses gps and gsm technology	b．it is put within about 3 meters
c．it’s joined to parents’ computer	d．it is fastened to the child’s wrist

小题2:if a child is wearing the “wristwatch”, parents can track them by .

a．sending the text message “wru”	b．replying to the text message
c．getting a google maps picture	d．phoning the local police station

小题3:what can we conclude from the text?

a．it won’t be easily found if a child loses t11e device

b．the device won’t work while a child is swimming

c．parents can easily track children due to the device

d．the new product needs to be fully charged daily

小题4:the purpose of the text is to .

a．explain how to use the new device

b．attract more buyers to the new product

c．discuss advantages of a new invention

d．introduce a new electronic equipment