问题 填空题

三角形三边长度是三个连续自然数,且三角形的周长小于18,那么这个三角形的三边长分别是______.

答案

设这三个自然数是x,x+1,x+2,

x+x+1+x+2<18,

解得:x<5,

∵x为自然数,

∴x可取1,2,3,4,

①当x=1时,这三角形的三边长为:1,2,3,构不成三角形,故不成立;

②当x=2时,这三角形的三边长为:2,3,4,符合题意;

③当x=3时,这三角形的三边长为:3,4,5,符合题意;

④当x=4时,这三角形的三边长为:4,5,6,符合题意.

故答案为:4,5,6;3,4,5;2,3,4.

阅读理解

阅读理解。

      The customs in different countries are rather different. If I have dinner with a Chinese host, he always

puts more food onto my plates as soon as I have emptied it. That often discomforts me greatly. I have to eat

the food even if I don't want to, because it is considered (认为) bad manners in the West to leave one's food

on the plate. I have already noticed that when a Chinese sits at an American's dinner party, he very often

refuses (拒绝) the offer of food or drink though he is in fact still hungry or thirsty. This might be good

manners in China, but it is not in the West at all. In the United States, it is impolite to keep asking someone

again and again or insist on his accepting something. Americans have a direct (直接的) way of speaking. If

they want something, they will ask for it. If not, they will say, "No, thanks." When an American

dislikes the beer served by the host, for example, he might say, "No, thanks. I'll take some diet Coca-Cola

(可口可乐) if you have it." That is what an American will do. So when you go to the United States, you

had better remember the famous saying: When in Rome, do as the Romans do.

1. From the passage, we can know that the Chinese are usually _______ to the guests. [ ]

A. very hot

B. rude

C. impolite

D. cold

2. When a foreigner has dinner with a Chinese host, he often feels_______. [ ]

A. pleasant

B. uncomfortable

C. satisfied

D. happy

3. Why does a Chinese often refuse the offer of food or drink at a dinner party? [ ]

A. He has had enough.

B. He is shy.

C. He is afraid that others will laugh at him.

D. He thinks it's polite to do that.

4. When an American wants something to eat or drink at a dinner, he will _______. [ ]

A. ask for it through others

B. refuse the offer

C. ask for it directly

D. express himself indirectly (间接地)

5. "When in Rome, do as the Romans do" means "_______". [ ]

A. When you got to Rome, you should act as the Romans do

B. When you stay in Rome, you should do as the Romans do

C. When you are in a new country, you should do as the locals (当地人) do

D. Romans can be aft example for you

选择题