F.

名词 f.:

1. a degree on the Fahrenheit scale of temperature
   同义词：degree Fahrenheit, F
2. a nonmetallic univalent element belonging to the halogens; usually a yellow irritating toxic flammable gas; a powerful oxidizing agent; recovered from fluorite or cryolite or fluorapatite
   同义词：fluorine, F, atomic number 9
3. the capacitance of a capacitor that has an equal and opposite charge of 1 coulomb on each plate and a voltage difference of 1 volt between the plates
   同义词：farad, F
4. the 6th letter of the Roman alphabet
   同义词：F, letter f