How to get the systemd resolver to resolve local (i.e. unqalified) names?

[Chris Green]

Before the systemd-resolved came along my systems resolved local (i.e.
unqualifed) names quite happily, e.g. on my older xubuntu 16.04
systems I can do:-

        chris at backup:~$ host esprimo
        esprimo.zbmc.eu has address 192.168.1.3
        chris at backup:~$ host esprimo.zbmc.eu
        esprimo.zbmc.eu has address 192.168.1.3
        chris at backup:~$ host pi
        pi.zbmc.eu has address 192.168.1.2
        chris at backup:~$

... but on a new 17.04 system running systemd-resolved:-

        chris$ host esprimo
        Host esprimo not found: 2(SERVFAIL)
        chris$ host esprimo.zbmc.eu
        esprimo.zbmc.eu has address 192.168.1.3
        chris$ host pi
        Host pi not found: 2(SERVFAIL)
        chris$

There is a local DNS server running on the LAN which provides DHCP and
DNS to all systems.  As can be seen from above the older systems (not
using systemd-resolver) seem to send the unqualified name requests to
the DNS system and get the right result.  How can I configure
systemd-resolved to do the same thing?

-- 
Chris Green