Green is an important color in nature. It is the color of grass and the leaves on trees. It is the color of most growing plants,too.

Sometimes, the word green means young,fresh and growing. Sometimes,it describes something that is not yet finished or plants that are not ripe.

For example,a greenhorn is someone who has no experience,who is new to a situation. In the fifteenth century,a greenhorn was a young cow or ox whose horns had not yet developed. A century or so later,a greenhorn was a soldier who had not yet had any experience in war（战争）.By the eighteenth century,a greenhorn had the meaning it has today——a person who is new in a job.

About one hundred years ago,greenhorn was a popular expression in the American west Old—timers used it to describe a man who had just arrived from one of the big cities in the east. The greenhorn didn't have the skills that he would need to live in the hard,rough country.

Someone who has the ability to grow plants well is said to have a green thumb. The expression comes from the early nineteen hundred.

A person with a green thumb seems to have a magic touch that makes plants grow quickly and well. You might say that the woman next door has a green thumb if her garden continues to grow long after your plants have died.

The Green Revolution（革命）is the name which was given some years ago to the development of new kinds of rice and other grains. The new plants produced much larger crops. The Green Revolution was the result of hard work by agricultural（农业的）scientists who had green thumbs.

The expression "down to earth" means being open and honest.   It is easy to get on with someone who is down to earth.   A down-to-earth person is the opposite of someone who acts important or proud.

Down-to-earth people could be important members of society.   But they do not consider themselves to be better than others who are less important.   A person who is filed with his own importance and pride is said to have his nose in the air.

Americans use another expression that is similar in some ways to down to earth.     The expression is both feet on the ground.     Someone with both feet on the ground is a person with a good understanding of realty(现实).   He may have dreams, but he does not allow them to have influence on his understanding of what is real.

The opposite kind of person is one who has his head in the clouds.     Someone with his head in the clouds is a person whose mind is not on what is happening in real life.   Such a person may be called a day-dreamer.

When we have both our feet on the ground and when we are down to earth.   we do not have our noses in the air.   We act honestly and openly to others.   Our lives are like the ground below us-solid(牢固的)and strong.

English is the most widely used language in the history of our planet. One in every seven human beings can speak it. More than half of the world’s books and three quarters of international mail are in English. Of all languages, English has the largest vocabulary — perhaps as many as two million words.

However, let’s face it: English is a crazy language. There is no egg in an eggplant, neither pine nor apple in a pineapple and no ham in a hamburger. Sweet-meats are candy, while sweetbreads, which aren’t sweet, are meat.

We take English for granted. But when we explore its paradoxes (探讨它的矛盾), we find that quicksand can work slowly, boxing rings are square,   public bathrooms have no baths in them.

And why is it that a writer writes, but fingers don’t fing, grocers don’t groce, and hammers don’t ham? If the plural of tooth is teeth, shouldn’t the plural of booth be beeth? One goose, two geese — so one moose, two meese?

How can a slim chance and a fat chance be the same, while a wise man and a wise guy are opposites? How can overlook and oversee be opposites, while quite a lot and quite a few are alike? How can the weather be hot as hell one day and cold as hell the next?

English was invented by people, not computers, and it reflects (反映) the creativity of human beings. That’s why, when stars are out, they are visible (能看见的); but when the lights are out, they are invisible. And why, when I wind up my watch, I start it; but when I wind up this essay, I end it.