The non-radial p modes and g modes appear simultaneously in the red giant stars. The variation rates of their frequencies are different along the stellar evolution so that their frequencies will become close and the avoided crossings arise between them. The separation between acoustic waves and gravity waves propagation regions for $l$ = 1, 2 and 3 is different which results in the coupling efficiency is different too. In this paper, we present the results of numerical computations of the models we choose. We find the two kinds of modes for $l$ = 2 and 3 need to be closer in frequency to exchange nature completely than the case for modes of $l$ = 1. Their scaled oscillation frequencies also present better regularity than modes of $l$ = 1 with evolution. In order to study the effect of avoided crossings in detail, we choose the mode which has the smallest mode inertia as p modes. We plot the two kinds of modes for $l$ = 1, 2 and 3 in frequency and period \'{e}chelle diagrams and find modes of $l$ = 2 and 3 fit better to the two relations of equally spaced in frequency and period than modes of $l$ = 1. Under careful observations of two kinds of \'{e}chelle diagrams of $l$ = 2 and 3, we still find some p modes shift a little from equally spaced in frequency and some g modes which are close to those p modes in period shift a little from equally spaced in period. Then, we study the relation between the deviation from equally spaced law in period and the mode inertia of g modes for different $l$. g modes of $l$ = 1 with a period closer to p modes has less inertia and the deviation is bigger in the period \'{e}chelle diagram and their deviation is obvious. However g modes of $l$ = 2 and 3 shift a little or almost have no deviation to equally spaced in period even though some of them may have strong coupling and close mode inertia as the p mode has. So, we suggest a possible method that the mixed g modes of $l$ = 2 and 3 could be used for measuring period spacing of g modes precisely with less observed mixed g modes than the case for $l$ = 1.
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