2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/47723It is presented a critical consideration of all unusual properties of the scalar $a_0(980)$ and $f_0(980)$-mesons in the four-quark, two-quark and molecular models. The arguments are adduced that the four-quark model is more preferable. It is discussed the complex of experiments that could finally resolve this issue.13 pages, revtex, a typo in Eq. (43) is removed, to be published in Uspekhi Fizicheskikh Nauk, V. 168, No 11, 1998High Energy Physics - PhenomenologyHigh Energy Physics - Experimenttext