植物体内的多糖包括淀粉和纤维素，它们水解后的单体分别是    

下列各组词语中，有错别字的一项是（    ）

2RCOOH+2CH₂=CH₂+O₂ 2CH₂=CHOOCR+2H₂O

葡萄糖在酒化酶的作用下生成有机物A；B是石油化学工业最重要的基础原料。A、B、C、D、E间的转化关系如下图：

完形填空。
    Do you know? There is one language 1 in every country in the world. People, young or old, short or tall, thin or fat, use it very often. It is everybody’s second2 . It is very easy to3, though you can't hear it. It is a sign language.
    When you wave(挥手) to a friend on the street, you are 4sign language. When you 5 up your hand in class, you are saying, “Please ask me, I think I know the answer,” or “I have some questions to6.” When you smile at someone, you mean to be 7to him. When you put your forefinger(食指) in front of your mouth, you mean, “8 quiet, please.” When a policeman wants to 9cars or buses, he raises his right arm. Sign language is very useful in quiet places or places 10 of noise. It is different from body language.