Two-body decays of charm mesons (except for decays into the final states involving 7 or 7') are studied from a perspective in which dynamical contributions of hadrons are explicitly taken into account. All the observed values of branching ratios for the two-body decays of charm mesons are reproduced well. In particular, a solution to the well-known puzzle,is presented. Contributions of exotic ( Q Q ) (~Q ) mesons can explain the large violation of the charm counterpart of the / A 1 I =+ rule in consistency with the small violation of the AZI = + rule in the K-a.rr decays. PACS number(s): 13.25. +m, 11.30.Hv, 14.40.J~ The fact that the D o +RO$ decay [which is described by the so-called annihilation type of quark-line diagrams in the infinite weak-boson-mass limit ( m + m )] has a sizable rate [I] implies that long distance effects are important in nonleptonic weak decays of charm mesons. In the past, explicitly taking into account dynamical contributions of various hadrons, we have studied nonleptonic weak decavs of K and charm mesons and have obtained good results on the approximate A I 1 = f rule in the K -m-r decays [2], the sizable rate [3] of D O +KO+, and the strong suppression [4] of F + -T +~~. In particular, we have demonstrated [5] that the observed large ratio [I], which is a long-standing puzzle, can be reproduced remarkably well by taking into account contributions of exotic four-quark mesons [6] to the intermediate states of the decay processes. However, in Ref. [5] we picked out only the contribution of the [QQ][QQ] but not that of the (QQ )(GQ) mesons. Therefore, the predicted rate of the D ++.rr+RO decay was very small in disagreement with experiment [I]. In this paper, we study typical twobody decays of charm mezojs by taking into account contributions of the (QQ )(QQ) mesons and a glueball in addition to those of the ground-state { QQ lo and the exotic [QQ][GG] mesons which were taken into account in Ref. [5] and demonstrate that all the observed values of the branching ratios for the two-body decays of charm mesons can be well reproduced. In particular, a solution to the well-known puzzle, is presented without contradiction to the other decays. The contributions of exotic (QQ )(QQ) mesons can explain the large violation of the charm counterpart of the IAIl=f rule in consistency with the small violation of the I AI 1 =+ rule in the K +an-decays.We start from a very useful expression for the decay amplitude which manifests dynamical contributions of hadrons. The amplitude for a three-pseudoscalar (PSImeson process, P , ( p )-P2( k) + P 3 ( q ) , can be approximated in the form [2,7,8] which is realized by using the partially-conserved axialvector current (PCAC) hypothesis and an extrapolation q+O in the light-cone frame [(LCF), i.e., p+ m 1. The above approximation can be considered as an innovation of the old soft-pion technique [9]. Here, the equal-time commutator (ETC) term, and the surface term M s , which vanishes in the soft PS meson extrapolation but now survives,