The Indians invented and developed the system of numbers from 1 to 9 and 0. We can use the ten numbers to make any number from the biggest to the smallest.

　 However, the ancient Romans invented a different system (系统) of numbers. They used symbols (符号) and replaced them. 1 is “Ⅰ” and 2 is “Ⅱ”. For larger numbers, they invented new symbols—5 is “Ⅴ”, 10 is “Ⅹ”, and so on. But they didn’t have a symbol for zero.

　 Here’s a table of the Roman numbers.

　 The Romans combined their symbols. In this way, “Ⅶ” means “5+1+1”, or 7. However, they found that “ⅡⅡ” (for 4) and “ⅤⅡⅡ” (for 9) were too confusing, so they thought out another idea.

　 If the “Ⅰ” comes after the “Ⅴ”, then you add it (Ⅵ is 6); if the “Ⅰ” comes before the “Ⅴ”, then you subtract (减去) it (Ⅳ is 4). The rule is that you are allowed to add up to three (e.g. Ⅷ is 8), but only subtract one (e.g. XL is 40).

　 How to remember the symbols?

　 Ⅰis like a finger. In a whole hand, the thumb (拇指) and the little finger make a V. Ten fingers are both hands, so the two Vs make an X..

　 Here is a way to remember the other symbols (L, C, D, M)：Little Cats Drink Milk.

(　 ) 51. How many numbers can we make according to the Indians’ system ?

　　　　 A. three: 0, 9, 1　　 B. ten　　　　　 C. eleven　　　 D. lots of

(　 ) 52. Which number was not in the ancient Roman’s number system?

　　　　 A. 1　　　　　　 B. 9　　　　　 C. 0　　　　　　 D. 5

(　 ) 53. What does the underlined word “combined” probably mean in the passage?

　　　　 A. 合并　　　　 B. 分离　　　　 C. 增加　　　　 D. 削减

(　 ) 54. What does MD mean according to the Romans’ rule of calculating?

　　　　 A. 500　　　　　 B. 1000　　　　 C. 1500　　　　 D. 2000

(　 ) 55 Which sentence is NOT true according to the passage?

　　　　 A. “Little Cats Drink Milk” can help us to remember some of the numbers symbols.

　　　　 B. The Indians invented the system of numbers from 1 to 9 and 0.

　　　　 C. You are not allowed to make a number like “XXL”

　　　　 D. The ancient Romans repeated symbols to make any number.

Hi Hongbo,
I’m so glad to read about the changes talking place in your city. It’s really good news that you can travel by subway in Xi’an, though there’s only one line there. Here in London we have twelve lines. By the way, we don’t use the word “subway” here. It’s American English. We call it “the Underground”, instead.
The London Underground is very famous. It’s famous for several reasons. First of all, part of the underground railway today is the oldest in the world, which opened in 1863. Secondly, the London Underground is also the first line to have electric trains, in 1890. Thirdly but not the last, the London Underground is the second largest metro system in the world, after the Shanghai Metro. There are 270 stations in the Underground and it has 402 kilometres of tracks(轨道). What’s more, the city of London itself helps make the transportation system famous! I’ve got a few photos to help you build a clear picture of the Underground in my city. They are together with this mail.
In your email, you also said workers were building more lines. I’m sure your city is developing fast. Maybe you can send me a few photos of your city today. I really want to see the changes taking place there. I’m happy for you to live there in an ancient city with such a new look!
So much for now. I’ll write soon again. Best wishes!
【小题1】 Where is the writer from？

Hi Hongbo,

I’m so glad to read about the changes talking place in your city. It’s really good news that you can travel by subway in Xi’an, though there’s only one line there. Here in London we have twelve lines. By the way, we don’t use the word “subway” here. It’s American English. We call it “the Underground”, instead.

The London Underground is very famous. It’s famous for several reasons. First of all, part of the underground railway today is the oldest in the world, which opened in 1863. Secondly, the London Underground is also the first line to have electric trains, in 1890. Thirdly but not the last, the London Underground is the second largest metro system in the world, after the Shanghai Metro. There are 270 stations in the Underground and it has 402 kilometres of tracks(轨道). What’s more, the city of London itself helps make the transportation system famous! I’ve got a few photos to help you build a clear picture of the Underground in my city. They are together with this mail.

In your email, you also said workers were building more lines. I’m sure your city is developing fast. Maybe you can send me a few photos of your city today. I really want to see the changes taking place there. I’m happy for you to live there in an ancient city with such a new look!

So much for now. I’ll write soon again. Best wishes!

1. Where is the writer from？

2. The second paragraph mainly tells us        ?

3.In the email, the words “subway”, “underground”, and “metro” mean         .

4. What does the writer want Hongbo to do?