the baseline problem on minipage in subfigure

The baseline problem on minipage in subfigure (see the manual of subfigure):

The baseline of the subfigure is usually at the bottom of the subfigure or (when the subcaption appears at the top) at the bottom of the subcaption and the \subfigcapskip space—which is usually the same as the top of the subfigure. However sometimes, especially when using the tabular, array, or minipage environments to build the figure, the baseline appears elsewhere. The above environments are all aligned at their center by default but that may be changed with the optional `[t]' or `[b]' arguments.