Question

What kind of analogy is this sentence water is to moisten as spade is to dig

Answer 1

Water is used to moisten things like the land, earth, flowers etc
A spade is used to dig the earth,grond,sand,etc
Water and spade are both nouns
To moisten and to dig are both verbs.
Hence the analogy;

Answer 2

Function analogy

Step-by-step explanation:

The function of water is to moisten and the function of a spade (or blade) is to dig