Complex sentence: He was appointed First Secretary at the Chinese legation in Vienna in 1937, and when Austria was annexed by Nazi Germany in 1938 and the legation was turned into a consulate, Ho was assigned the post as Consul-General.
Split into simpler sentences: He was appointed First Secretary at the Chinese legation in Vienna in 1937. When Austria was annexed by Nazi Germany in 1938, and the legation was turned into a consulate, Ho was assigned the post of Consul-General.