Why is zero neither positive, nor negative?

Dear Sir/Madam,

OPRFID manufactures a full range of RFID products included contactless inlay, card, token, smart keyfob, smart wristband, smart button, metal tag,NFC tags which are used for transportation, electronic payment, access control and identification applications around the world.

Regards,
Eva
OPRFID Technologies., LTD
2-603 Room, Hong Feng Jia Yuan , 270# BeiMo Street
ChengXiang Putian City Fujian, P.R, China.
Tel: (0086)594 2790031
Fax: (0086)594 2790185
Mobile:(0086)13599454033
Email:oprfid.eva@oprfid.com
MSN:eva.oprfid@hotmail.com
skype:oprfid.eva
www.oprfid.com