 Complete the following phrase:  The Matilda was first used in combat by the 7th Royal Tank Regiment in France in 1940. Only 23 of the units tanks were Matilda IIs; the rest of the British infantry tanks in France were the smaller machine-gun armed A11 Matilda. Its 2-pounder gun was comparable to other tank guns in the 37 to 45 mm range. Due to the thickness of its armour, it was largely immune, but not impervious, to the guns of the German tanks and anti-tank guns in France. The Germans found the 88 mm anti-aircraft guns were the only effective counter-measure. In the counter-attack at Arras of 21 May 1940, 18 British Matilda IIs and Matilda Is were able to briefly disrupt German progress, but, being unsupported, they sustained heavy losses 30 tanks lost after breaking through to the rear area of 7th Panzer Division. A gun line of artillery and later 88mm flak guns, personally organised by General Rommel was needed to repel the attack. All vehicles surviving the battles around 