In this part there is a short passage with five questions or incomplete statements. Read the passage carefully. Then answer the questions or complete the statements in the fewest possible words (not exceeding 10 words). A strict vegetarian is a person who never in his life eats anything derived from animals. The main objection to vegetarianism on a long-term basis is the difficulty of getting enough protein—the body-building element in food. If you have ever been without meat or other animal foods for some days of weeks (say, for religious reasons), you will have noticed that you tend to get physically rather weak. You are glad when the fast is over and you get your reward of an abundant meat meal. Proteins are built up from approximately twenty food elements called “amino-acids ( 氨基酸 )”, which are found more abundantly in animal protein than in vegetable protein. This means you have to eat a great deal more vegetable than animal food in order to get enough of these amino-acids. A great deal of the vegetable food goes to waste in this process and from the physiological point of view there is not much to be said in favor of life-long vegetarianism. The economic side of the question, though, must be considered. Vegetable food is much cheaper than animal food. However, since only a small proportion of the vegetable protein is useful for body-building purposes, a consistent vegetarian, if he is to gain the necessary 70 grams of protein a day, has to consume a greater bulk of food than his digestive organs can comfortably deal with. In fairness, though, it must be pointed out that vegetarians claim they need far less than 70 grams of protein a day. Why is the long-term vegetarianism objected to according to the passage? In the author’s opinion, we feel weak when we———————— If someone is a vegetarian, what does he/she have to do in order to get enough protein to support his/her body? What is in favor of vegetarianism according to Paragraph 3? How much food can the digestive organs comfortably deal with per day?