context: Since 1947, Canadian military units have participated in more than 200 operations worldwide, and completed 72 international operations. Canadian soldiers, sailors, and aviators came to be considered world-class professionals through conspicuous service during these conflicts and the country's integral participation in NATO during the Cold War, First Gulf War, Kosovo War, and in United Nations Peacekeeping operations, such as the Suez Crisis, Golan Heights, Cyprus, Croatia, Bosnia, Afghanistan, and Libya. Canada maintained an aircraft carrier from 1957 to 1970 during the Cold War, which never saw combat but participated in patrols during the Cuban Missile Crisis.
question: প্রায় ১৫ বছর ধরে কোন ধরনের সামরিক যানবাহন রক্ষণাবেক্ষণ করা হয়েছিল কিন্তু কিউবার সংকটের সময় কোন পদক্ষেপ কখনও দেখা যায়নি?
answers: an aircraft carrier