An agency may:
(a) Exercise all or any part or combination of the powers granted in Sections 33651 to 33658 inclusive.
(b) Make covenants other than and in addition to the covenants expressly authorized in such sections of like or different character.
(c) Make such covenants and to do any and all such acts and things as may be necessary, convenient, or desirable to secure its bonds, or, except as otherwise provided in this part, as will tend to make the bonds more marketable notwithstanding that such covenants, acts, or things may not be enumerated in this part.