阅读理解。 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 hundreds. 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. 1. According to the passage, a greenhorn means ______ now. A. a young cow or ox whose horns have not yet developed B. a soldier who has not had any experience in war C. a person who is new in a job D. a man who doesn't have the skills to live in the country 2. The meaning of the underlined word 'ripe' in the second paragraph is ______. A. 未完成的 B. 成熟的 C. 青涩的 D. 老练的 3. Which of the following about the Green Revolution is NOT right? A. If there weren't the Green Revolution, we would have no rice to eat. B. The expression 'the Green Revolution' appeared several years ago. C. Because of the Green Revolution, we have more kinds of rice and other grains. D. Agricultural scientists with green thumbs started the Green Revolution. 4. We can know from the passage that ______. A. all growing plants is green B. green is the most important color in nature C. a person with a green thumb can make plants grow well D. the expression 'a green thumb' has a history of two hundred years 5. The main idea of the passage is ______. A. a greenhorn B. a green thumb C. the Green Revolution D. the word 'green' and its story