题目内容：

七选五

   1.  . Still, all flavors are based on just four basic tastes: sweet, bitter, salty, and sour. Some food experts argue there is a fifth basic taste called umami（a Japanese word that can be translated roughly as "tasty" or "savory"）, but this theory remains controversial.     2.

How can so few basic tastes give rise to the enormous number of flavors we experience?       3.     Compare this to colors. There are only three basic colors—yellow, red, and blue—but when mixed in different ways and proportions, these three basic colors are sufficient to create the vast array of colors that we see every day.

Apart from being influenced by different combinations of the basic tastes, the experience of taste is also enriched by other sensations, such as odor (气味) and temperature. These functions together produce what we recognize as unique tastes. In fact, what we perceive as taste often involves smell more than the taste experienced through the tongue.    4.   For example, cinnamon tastes quite mild to people who cannot enjoy its fragrant smell. The same is true of drinks, like hot coffee or tea, which taste best when they can be smelled and tasted.

5.    The reason why hot, spicy foods like chili peppers are tasty is that they affect the lingual nociceptors. Nociceptors are small areas on the surface of the body that help protect us against injury. Nociceptors on the skin warn us of potential damage to the body. When we are pricked with a needle, for example, nociceptors represent that sensation as pain. A special kind of nociceptor called a lingual nociceptor is found on the tongue and, along with the other senses, helps us enjoy certain foods.

A. These are basic tastes that we are familiar with.

B. This is possible because the basic tastes combine in different proportions.

C. Each food we eat tastes different, and there are untold numbers of different tastes.

D. This is why foods with strong tastes often seem unattractive to people who, due to a stuffy nose, cannot smell them.

E. What can also contribute to the sensation of taste is our ability to feel pain.

F. So there are a small number of basic tastes that affect a big number of flavors.

G. Regardless of whether there are four or five basic tastes, the number is small.