Question: Only a few of the 105 mm static mounting AA guns were produced because work had started on which other gun?
Sentence: However, in 1924 work started on a new 105 mm static mounting AA gun, but only a few were produced by the mid-1930s because by this time work had started on the 90 mm AA gun, with mobile carriages and static mountings able to engage air, sea and ground targets.
Answer in sentence: yes