Each passage below is accompanied by a number of questions. For some questions, you will consider how the passage might be revised to improve the expression of ideas. For other questions, you will consider how the passage might be edited to correct errors in sentence structure, usage, or punctuation. A passage or a question may be accompanied by one or more graphics (such as a table or graph) that you will consider as you make revising and editing decisions.
Some questions will direct you to an underlined portion of a passage. Other questions will direct you to a location in a passage or ask you to think about the passage as a whole.
After reading each passage, choose the answer to each question that most effectively improves the quality of writing in the passage or that makes the passage conform to the conventions of standard written English. Many questions include a “NO CHANGE” option. Choose that option if you think the best choice is to leave the relevant portion of the passage as it is.
Whey to Go
Greek yogurt—a strained form of cultured yogurt—has grown enormously in popularity in the United States since it was first introduced in the country in the late 1980s.
From 2011 to 2012 alone, sales of Greek yogurt in the US increased by 50 percent. The resulting increase in Greek yogurt production has forced those involved in the business to address the detrimental effects that the yogurt-making process may be having on the environment. Fortunately, farmers and others in the Greek yogurt business have found many methods of controlling and eliminating most environmental threats.
Given these solutions as well as the many health benefits of the food, the advantages of Greek yogurt outdo Q1 the potential drawbacks of its production.
 The main environmental problem caused by the production of Greek yogurt is the creation of acid whey as a by-product.  Because it requires up to four times more milk to make than conventional yogurt does, Greek yogurt produces larger amounts of acid whey, which is difficult to dispose of.  To address the problem of disposal, farmers have found a number of uses for acid whey.  They can add it to livestock feed as a protein supplement, and people can make their own Greek-style yogurt at home by straining regular yogurt. Q2
 If it is improperly introduced into the environment, acid-whey runoff can pollute waterways , Q3 depleting the oxygen content of streams and rivers as it decomposes.  Yogurt manufacturers, food scientists; and Q4 government officials are also working together to develop additional solutions for reusing whey.Q5 Though these conservation methods can be costly and time-consuming, they are well worth the effort.Q6 Nutritionists consider Greek yogurt to be a healthy food: it is an excellent source of calcium and protein, serves to be Q7 a digestive aid, and it contains Q8 few calories in its unsweetened low- and non-fat forms. Greek yogurt is slightly lower in sugar and carbohydrates than conventional yogurt is. Also , Q9 because it is more concentrated, Greek yogurt contains slightly more protein per serving, thereby helping people stay
satiated Q10 for longer periods of time. These health benefits have prompted Greek yogurt’s recent surge in popularity. In fact, Greek yogurt can be found in an increasing number of products such as snack food and frozen desserts. Because consumers reap the nutritional benefits of Greek yogurt and support those who make and sell it, therefore farmers Q11 and businesses should continue finding safe and effective methods of producing the food.