题目

Many animals recognize their food because they see it. So do humans. When you see an apple or a piece of chocolate you know that these are things you can eat. You can also use other senses when you choose your food. You may like it because it smells good or because it tastes good. You may dislike some types of food because they do not look, smell or taste very nice. Different animals use different senses to find and choose their food. A few animals depend on only one of their senses, while most animals use more than one sense.    Although there are many different types of food, some animals 方程表示的图形是 [     ]A．一条直线及一个圆B．两个点 C．一条射线及一个圆 D．两条射线及一个圆