单选题 Why do Southern farmers shift to planting sugar, peanuts and other kinds of crops?
A. Because farmers don't think it a good way to raise cotton and tobacco together.
B. Because farmers find they can become richer only when they plant these things.
C. Because if they just raise cotton and tobacco, the unstable price will probably cause them to suffer an economic loss.
D. Because world prices for these things are relatively stable.

【正确答案】 C

【答案解析】[解析] 17-20
For many years, cotton and tobacco were the South's only agricultural products of any importance. In the mid-twentieth century, however, southern farmers began to rely less and less upon one crop to earn a living. World prices of cotton and tobacco often vary greatly. Therefore, a sudden fall in the price of either can cause economic suffering to those who depend solely on one crop for income. Consequently, many southern farmers now raise sugar, peanuts, corn, rice and a wide variety of garden vegetables. Citrus fruits are also grown in large quantities, esp. in Florida where they can receive warmth and sunlight all year long.
The other major economic activities in the region include mining, fishing, steel and other heavy industries and tourism. In Florida, income from tourism accounts for more than half the state's annual income during the winter months. The textile industry accounts for the employment of many people in the two Carolinas, and the U. S. military and space programs also contribute greatly to the economy of the region. The major launching centre for NASA, where all the space shuttle flights originate, is Cape Canaveral, on the coast of Florida. In addition, there are more army, navy, air force and marine bases in the south than in any other region of the U. S.