题目

Everyone knows that fish is good for health. 31 But it seems that many people don't cook fish at home. Americans eat only about fifteen pounds of fish per people per year, but we eat twice as much fish in restaurants as at home. Buying, storing, and cooking fish isn't difficult. 32 This text is about how to buy and cook fish in an easy way. 33 Fresh fish should smell sweet: you should feel that you’re standing at the ocean’s edge. Any fishy or strong smell means the fish isn’t fresh. 34 When you have bought a fish and arrive home, you’d better store the fish in the refrigerator已知直线：与：垂直，则等于A.                   B.             C. 0或          D. 或