 Complete the following phrase:  The German Army invaded in the West on 10 May 1940, by that time BEF consisted of 10 divisions, a tank brigade and a detachment of 500 aircraft from the RAF. During the Battle of France the speed of the German advance pushed them back, and after a brief armoured counterattack by the 5th and 50th Divisions, plus 74 tanks from the 1st Army Tank Brigade at Arras on 21 May, most of the BEF 