【明報專訊】In dealing with a recent robbery case, Hong Kong police successfully tracked down two lost suitcases containing large amounts of money with the help of the GPS (Global Positioning System) function of the mobile phones in the pieces of luggage. GPS is now used in many areas of life to help locate people or things anywhere on earth.

GPS is made up of three parts: ground stations, satellites and receivers. A receiver, like that you might find in your mobile phone, is constantly listening for a signal from the satellites. Once it calculates its distances from the satellites, your location will be determined with precision.

(sources: Ming Pao, NASA)

■English highway﹕luggage

"Luggage" is an uncountable noun that refers to the suitcases and bags you carry when you travel.

e.g. The bellboy carried our luggage to our room.

■Game １

According to the latest intelligence (情報), Eason is hiding in one of the five grids marked with "?". Bill is in the red grid. He can reach Eason if he follows the instructions written on the grids. Can you find out Eason's exact location?

(Hint: 1N = move 1 grid to the north)

■Game ２

If it takes 5 minutes for Bill to move 1 grid, how long will it take for him to reach Eason?

(Answers on next text)

“ Bill: Here you are! ”

“ Eason: Go away! I want a quiet Easter break. ”

■Glossary

track down (phr v) 追蹤到

satellite (n) 衛星

constantly (adv) 不斷地

precision (n) 精確

[Smarties' Power English Vol 183]