 Complete the following phrase:  After the First World War, Harrison remained with the British military, becoming adjutant of the Royal Military Academy, Woolwich from 1919 until 1921. He transferred from the Royal Marines to the British Armys East Yorkshire Regiment in 1924 and was brevetted lieutet colonel in 1927. He then spent some years serving in different posts in Asia. He served in Singapore from March 1923 until April 1924, where he was General Staff Officer Grade 3 GSO3 before being posted to British Malaya until 1925 as GSO 2. Between 1925 and 1928 he served as a GSO2 in the War Office. He was posted to India in 1930, becoming an instructor at the Staff College, Quetta, achieving the full rank of lieutet colonel in 1932. That same year he was given a role in the Imperial Defence College and from 1932 until 1935 he commanded the 1st Battalion of the Green Howards. From 1935 to 1937 he was a GSO1 of British Troops in China. From 1937 to 1939 he was posted to Palestine, then the scene of an 