【正确答案】：
GROUP 1 TELLS US THAT EVERY COMPOUND EXPRESSES A SINGLE IDEA AS ONE WORD, WHICH IS ONE OF THE SEMANTIC FEATURES OF COMPOUNDS. FOR EXAMPLE, “A GREEN HAND” MEANS “AN INEXPERIENCED PERSON”. THE MEANINGS OF SUCH EXAMPLES CANNOT BE EASILY INFERRED FROM THE TWO COMPONENTS OF THE COMPOUNDS. HOWEVER, A LOT OF COMPOUNDS ARE TRANSPARENT, THAT IS, THE MEANING CAN BE INFERRED FROM THE SEPARATE ELEMENTS OF COMPOUNDS, WHICH IS ANOTHER SEMANTIC FEATURE OF COMPOUNDS. AND ELEMENTS ARE INSEPARABLE AND THE CHANGE OF THE ELEMENT WOULD RESULT IN THE LOSS OF THE ORIGINAL IDENTITY, FOR EXAMPLE, “FLOWERPOT” MEANS “POT FOR GROWING PLANTS”. 
GROUP 2 REVEALS THE GRAMMATICAL FEATURES OF COMPOUNDS—PLAYING A SINGULAR GRAMMATICAL RULE IN A SENTENCE, FOR EXAMPLE, A VERB, A NOUN, OR AN ADJECTIVE. BAD-MOUTH USED AS A VERB CAN TAKE THE THIRD PERSON SINGULAR –S AND THE PAST TENSE MARKER –ED, E.G., “HE BAD-MOUTHED ME.” "NEW-BORNS" IS A COMPOUND SHOWING ITS PLURAL FORM BY TAKING INFLECTIONAL –S AT THE END.
【题目解析】：本题可从复合词的语义特点和语法特点入手。第一组告诉我们，每个复合词以一个（整体的）词表达一个单一的思想，这是复合词的语义特点之一。例如，“a green hand（ 表面意义是绿色的手）”的意思是“没有经验的人”。这样的例子的意义不容易从复合词的两个组成部分推断出来。然而，许多复合词是透明的，也就是说，意义可以从复合词的独立元素中推断出来，这是复合词的另一个语义特征。而元素是不可分割的，元素的变化会导致原有身份的丧失，例如，“花盆”的意思是“种植植物的花盆”。第二组揭示复合词的语法特点——在句子，例如动词、名词或形容词中扮演单数语法规则。用作动词的“诽谤”可以用第三人称单数-s和过去时标记-ed来修饰，例如“他骂了我”。新生儿是复合词，在结尾处用屈折语-s来表示其复数形式。