Complex sentence: In the Second World War Macmillan at last attained office, serving in the wartime coalition government as the Parliamentary Secretary to the Ministry of Supply from 1940 to 1942, providing armaments and other equipment to the British Army and Royal Air Force.
Split into simpler sentences: In the Second World War Macmillan at last attained office, serving in the wartime coalition government as the Parliamentary Secretary to the Ministry of Supply from 1940 to 1942. The task of the department was to provide armaments and other equipment to the British Army and Royal Air Force.