a. 没有饱和的,不饱和的

Unsaturated \Un*sat"u*ra`ted\, a.
1. Capable of absorbing or dissolving to a greater degree;
as, an unsaturated solution.

2. (Chem.) Capable of taking up, or of uniting with, certain
other elements or compounds, without the elimination of
any side product; thus, aldehyde, ethylene, and ammonia
are unsaturated; benzene has three unsaturated bonds. The
term is applied most commonly to compounds with a double
or triple bond between two carbon atoms (as in ethylene).
[1913 Webster +PJC]