Questions 1-11 are based on the following passage.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 1 outdo
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 2 supplement, and people can make their own Greek-style yogurt at home by straining regular yogurt.
If it is improperly introduced into the environment, acid-whey runoff 3can pollute waterways,
depleting the oxygen content of streams and rivers as it decomposes. 
Yogurt manufacturers, food 4 scientists; and
government officials are also working together to develop additional solutions for reusing whey.56Though these conservation methods can be costly and time consuming,they are well worth the effort.
Nutritionists consider Greek yogurt to be a healthy food: it is an excellent source of calcium and protein,serves 7 to be
digestive aid, and 8it contains
few calories in its unsweetened low- and non-fat forms. Greek yogurt is slightly lower in sugar and carbohydrates than conventional yogurt is. 9Also,
because it is more concentrated, Greek yogurt contains slightly more protein per serving, thereby helping people stay 10satiated
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 11it, therefore farmers
and businesses should continue finding safe and effective methods of producing the food.