“…Compared with the existing works, this paper has the following features. Firstly, the fractional derivative discussed in this paper is the standard Riemann-Liouville derivative, which is different from [8,9], and the linear operator of the FBVP we are considered with contains two terms, which is different from [14,19,27,28,30]; in other words, we discuss different problem which has been seldom studied before. Secondly, some meaningful properties of the Green's function for the case that 2 < α < 3 are established; this is different from [20] since Ref.…”