2010年12月英语四级考试模拟试题及答案(2)
Part I Writing (30 minutes)
Directions: For this part, you are allowed 30 minutes to write a composition on the topic: Styles of Living. You should write at least 120 words following the outline given below in Chinese:
1. 有些人愿意和父母居住在一起
2. 有些人想自己独立居住
3. 我的看法
Styles of Living
Part II Reading Comprehension (Skimming and Scanning) (15 minutes)
Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions on Answer Sheet 1. For questions 1-7, mark
Y (for YES) if the statement agrees with the information given in the passage;
N (for NO) if the statement contradicts the information given in the passage;
NG (for NOT GIVEN) if the information is not given in the passage.
How Ice Cream Works
The U.S. ice cream industry sells about a million gallons of ice cream each year, dispensing cones, gallons, pints, sundaes and other desserts through grocery stores and ice cream shops. In fact, eight percent of all the milk produced in the U.S. ends up in a frozen dairy product.
Ice Cream or Frozen Dessert?
Not just any frozen treat can be called ice cream. In fact, the U.S. Department of Agriculture has specific rules that define what can and can't be labeled "ice cream". To bear the "Meets USDA Ingredient Standard for Ice Cream" stamp, it has to contain at least 10 percent milk fat, and a minimum of six percent non-fat milk solids. A gallon has to weigh at least 4.5 pounds.
The range of milk fat (sometimes referred to as butter fat) used in ice cream can go from the minimum 10 percent to a maximum of about 16 percent. Most premium ice creams use 14 percent milk fat. Higher fat content leads to better, richer taste and a creamier texture. Ice cream makers don't go higher than 16 percent because it would be costly and very high in calories. An ice cream with this much milk fat would also taste so rich that people would probably eat it in smaller amounts, which would be bad news for people who sell ice cream for a living.
Other frozen desserts, such as sorbets (果汁冰糕), low-fat ice cream, and frozen yogurt, are not technically ice cream at all. Frozen custard is ice cream that has at least 1.4 percent egg yolk solids, and "soft serve" can be any frozen milkbased dessert that has not gone through the hardening process—more on that later.
In terms of specific ingredients, the recipe for ice cream is simple. But in scientific terms, it's complicated stuff. Ice cream is a colloid, a type of emulsion(乳状液). An emulsion is a combination of two substances that don't normally mix together. Instead, one of the substances is dispersed throughout the other. In ice cream, molecules of fat are suspended in a water-sugar-ice structure along with air bubbles. The presence of air means that ice cream is also technically a foam.
In addition to milk fat, non-fat milk solids, sugar, and air, ice cream also contains stabilizers and emulsifiers. Stabilizers help hold the air bubble structure together and give the ice cream a better texture. Although gelatin(凝胶) was originally used as a stabilizer, xanthan gum, guar gum, and other compounds are used today. Emulsifiers keep the ice cream smooth and aid the distribution of the fat molecules throughout the colloid. Egg yolks were once used, but ice cream manufacturers now tend to use other chemical compounds. These stabilizers and emulsifiers make up a very small proportion (less than one percent) of the ice cream.
