Thanks to all

[QUOTE=bear;203430]some units were wrong / needed explanation
i have corrected them


OHM……………...…………-------------Resistance (" Impedance " too)
FARADAY……………………-----------.capacitance( its called farad not faraday)
CURIE…………………………----------- radioactivity
ANGSTROM…………………----------- Length (lenghts of degree of nanometer used for wavelengths)
LIGHT YEAR…………………----------- Length(uqual to distance coverd by light in one year)
DIOPTR………………………------------- Power of Lens(reciprocal of focal length in meter)
RADIAN………………………------------ angle
SIEMEN………………………----------- conductivity or admittance
PARSEC………………………----------- distance between glaxies and stars etc.
BTU……………………………------------ Heat Energy
ACRE-FOOT…………………------------ Volume large water resorvoirs
MhO……………………………------------ conductivity ( substitute of siemens )
WALT--------------------------------------- ( sorry i dont know this one)


Q:2. Abbreviations...........

ETT…………………………( sorry)
DBS……………………… ( sorry)
TNT……………………… tri nitro toluene[/QUOTE]
DBS……………………… ( Database system)

i am too much confused about subject selection??
what should i have to do?