The crossword solutions for the term 'SO THAT'S HOW IT IS!' are AHA (3 letters), OHO (3 letters), and ISEE (4 letters). AHA is an expression of surprise or realization, often used when something is suddenly understood. OHO is an expression of surprise or realization, similar to AHA but with more emphasis. ISEE is an expression of understanding or agreement, often used when something is accepted as true. Together, these three expressions can be used to express a sudden understanding of a situation, such as 'So that's how it is!'