複選題28. Five students are discussing a peptide consisting of nine amino acid residues. Student A: When this peptide is digested by chymotrypsin, you can get a tripeptide and a hexapeptide. Student B: This peptide cannot be cut by cyanogen bromide. Student C: This peptide does not contain any amino acids with two chiral centers Student D: When this peptide is digested by trypsin, you can get a tripeptide and a hexapeptide. Student E: When I dissolved the peptide in 100 mM phosphate buffer (pH 7), this peptide is positively charged. What might be the peptide sequence?(A) MSEFAHKVW.(B) SERLLWATK.(C) QGEKCYIPC.(D) FHRGPWSSM.(E) CSKQAYNDR.