Haveyoueverheardsomeoneusethephrase“onceinabluemoon”?Pe...

问题详情：

Have you ever heard someone use the phrase“once in a blue moon”? people use this expression to describe something that they do not do very often. For example, someone might say that he tries to avoid eating sweets because they are unhealthy, but will eat chocolate once in a blue moon. Or someone who does not usually like to go to the beach might say “I visit the shore once in a blue moon.” While many people use this phrase, not everyone knows the meaning behind it.

The first thing to know is that the moon itself is never really blue. This is just an expression. In fact, the phrase” blue moon” has to do with the shape of the moon, not the color.

As the moon travels around the earth, it appears to change shape. We connect certain names with certain shapes of the moon. For example, when we can see a small part of the moon it is called a crescent moon. A crescent is a shape that looks like the tip(尖端) of a fingernail. When we cannot see the moon at all, it is called a new moon. When we can see the whole moon, it is called a full moon. Usually, there is only one full moon every month. Sometimes, however, there will be two full moons in one month. When this happens, the second full moon is called a “blue moon”.

     Over the next 20 years, there will only be 15 blue moons. As you can see, a blue moon is a very rare event. This fact has led people to use the expression“once in a blue moon” to describe other very rare events in their lives.21教育名师原创作品

（  ） does the writer write this passage?

A. To describe the shapes of the moon.

B. To explain how a new moon forms .

C. To teach us how to use the phrase “once in a blue moon”.

D. To tell us the meaning behind the phrase “once in a blue moon”.

（  ）2. What does the underlined part “When this happens” refer to?

A. When we cannot see the moon at all.

B. When the moon has a blue moon.

C. When we can see the whole moon.

D. When there are two full moons in one month.

（  ）3. The phrase“once in a blue moon” is mainly used to describe ________.

A. something we often do        B. everything we like to do  

C. something we hardly do       D. everything we hate to do  

（  ）4. Which of the following is another example of something that has a crescent shape?

A. The letter “D”              B. The letter “C”

C. The letter “H”              D. The letter “O”

（  ）5. How often will a blue moon happen over the next twenty years?

A. Less than once a year.         B. once a year.

C. More than once a year.          D. twice a year.

【回答】

1D 2D 3C 4B 5A

知识点：日常生活类

题型：阅读理解