There have been many ups and downs for Air Canada, but the company continues to control the majority of the domestic market. The underlined part means（ ）.
问题1选项
A.strengths and weaknesses
B.fortunes and misfortunes
C.assets and liabilities
D.bolts and nuts
考查名词辨析。A选项strengths and weaknesses“优势与劣势”；B选项fortunes and misfortunes“机遇与不幸”；C选项assets and liabilities“资产与负债”；D选项bolts and nuts“螺栓与螺帽，指基本的但很重要的组成部分”。ups and downs意为“起起伏伏、盛衰、浮沉”，B选项fortunes and misfortunes“机遇与不幸”与其最接近，因此B选项正确。句意：虽然加拿大航空公司经历了许多起起落落，但该公司仍然控制着大部分的国内市场。
