You might think that hamburgers were invented in the United States, but that is not totally true. These (1) , or patties, actually came from Germany in the middle of the nineteenth century. They were brought to the United States by (2) who came from the city of Hamburg. That is why (3) was "hamburger steak".
However, people in other places (4) that they invented the hamburger. Perhaps we’ll never have a (5) . But there’s no question that the hamburger was a (6) . Why Perhaps because at that time, industry was growing and a kind of (7) food was needed for workers.
The hamburger became even more popular (8) when the first chain of fast food restaurants was started. This chain was called "White Castle". It served tiny hamburgers that were sold for only (9) . Then, in the 1930s there came the (10) where customers were served in their cars by waiters in uniform. And the hamburger was one of the most (11) .
By now, The hamburger was ready to (12) the world. And this happened with McDonald’s, which was actually a (13) at first. But by the early 1950s the hot dog was replaced by the hamburger. McDonald’s and other fast food restaurants (14) around the world throughout the rest of the twentieth century. McDonald’s alone has (15) for everyone person in the world.
The importance of the hamburger to (16) remains significant. About (17) of all sandwiches that are eaten are hamburgers. According to some sources, (18) of current workers in the United States had their first job at McDonald’s. But the face of the hamburger is changing (19) . Nowadays it is possible to buy a chicken burger, a turkey burger, (20) , or veggie burger.
5（）
参考答案：clear answer
解析：
[听力原文]1-20 You might think that hamburgers were invented in the United States, but that is not totally true. These round fiat cakes (1), or patties, actually came from Germany in the middle of the 19th century. They were brought to the United States by German immigrants (2) who came from the city of Hamburg. That is why their name (3) was "hamburger steak". However, people in other places claim (4) that they invented the hamburger. Perhaps we’ll never have a clear answer (5). But there is no question that the hamburger was a great hit (6). Why Perhaps because at that time, industry was growing and the kind of fast, practical and cheap (7) food was needed for workers. The hamburger became even more popular in the 1920s (8)when the first chain of fast food restaurants was started. This chain was called "White Castle". It served tiny hamburgers that were sold for only 5 cents each (9). Then, in the 1930s there came the drive-in restaurant (10)where customers were served in their cars by waiters in uniform. And the hamburger was one of the most popular manual items (11). By now, the hamburger was ready to conquer (12) the world. And this happened with McDonald’s, which was actually a hot dog stand (13) at first. But by the early 1950s the hot dog was replaced by the hamburger. McDonald’s and other fast food restaurants spring up (14) around the world throughout the rest of the 20th century. McDonald’s alone has sold 12 hamburgers (15) for every person in the world. The importance of the hamburger to US culture (16) remains significant. About 60% (17) of all sandwiches that are eaten are hamburgers. According to some sources, 7% (18) of current workers in the Untied States had their first job at McDonald’s. But the face of the hamburger is changing according to the times (19). Nowadays it is possible to buy a chicken burger, a turkey burger, a fish burger (20), or a veggie burger.