任务型阅读: 有几位学生遗失了一些物品,请根据以下信息为他们写完寻物启事。

   Peter: I lost a gold watch. If you find it, call me at 680-7432.

   Jim :  I found a computer game. My phone number is 512-8843.

   Henry: I lost a set of keys. Who found them, please call 476-3539.

   Sam:  I found a notebook with the name "Kevin Clark". My phone number is 555-0287.

   Lost & Found

Found:                                               Lost:

     Is this your computer game?             2                  

     Please call Jim.                                 My name is Henry Cooper.

     Phone# 1                                         Please call me at 476-3539.

Lost:                                                 Kevin:

     A gold watch.                                  Is this your 4                  ?

     My name is 3             .                     Please call me at 5              .

     My phone number is 680-7432.                                 Sam.

什么是差速离心法？