19.Should there ______ any complaint from the endusers,pleas

19.Should there ______ any complaint from the endusers,please let us know.
(A) is
(B) have
(C) be
(D) arise
31.If you will send us a catalog by air,we shall ____ very much.
(A) appreciate
(B) appreciating
(C) appreciation
（D)appreciate it
33.Please note that we require the amendment ____ L/C by the end of October.
(A) to
(B) for
(C) at
(D) in
36.We are offering you goods ____ the very high quality.
(A) of
(B) at
(C) for
(D) with
翻译Please keep us posted of the developments in your market so that we can adjust our quotations to the extent you indicate.