英语翻译
A secound class of SI units comprises the deriver units,many of which have special name.Table1-4 is a list of those we shall find most useful in our work in this book.
The radian(symbol rad) is a supplemental unit in SI for a plane angle.
A series of names and symbols to form multiples and submultiples of SI units has been established to provide an alternative to the writing of powers of 10.Table A-1 includes these prefixes and symbols.