一粒种子能够萌发并长成一棵大树的主要原因是种子中具有（ ）
A．种皮
B．胚乳
C．胚
D．子叶
答案：C
题目分析：种子的结构包括种皮和胚，胚包括胚根、胚芽、胚轴、子叶四部分，当种子萌发时，吸水膨胀，种皮变软，呼吸作用逐渐增强，将储存在子叶或是胚乳中的营养物质逐步分解，转化为可以被细胞吸收利用的物质，输送到胚的胚轴、胚根和胚芽，在种子萌发初期，胚根生长最快，首先突破种皮向地生长，并发育成根，随后胚轴伸长，胚芽突破种皮背地生长，发育成茎和叶，通过这个过程，种子的胚就发育成了幼苗，幼苗逐渐长成一棵高大的植株，故选C。
My name is Steve. I move into this house __1_____ weeks ago, and I really enjoy__2_____here.There’s only one bedroom, and at the moment my sister is staying with me because she is __3____ a job. I work in a big company(公司).It’s hard__4____, and the hours are really long , but I like it. And it pays well. I don’t really __5____worried about my work. The only thing I don’t like about this house is one of the neighbors, Mrs.Snell, I think her name is. She’s really strange.She never speaks to___6____, I always says hello to her, and “ Are you all right?’ and what a lovely day today!”,but she never says a word.____ 7___she doesn’t like young people. My sister and I had a party a few days ago. It really wasn’t very noisy(吵闹). About ten of us were here____8___11.00pm and then we went out to dance. When I saw Mrs. Snell the next day, I said I hoped there wasn’t __9_____niose(噪音)for her, but as she didn’t saying anything. Funny lady. This evening my sister and I are going to visit a friend of ours who is in hospital, and then we ___10____out for a Chinese meal.
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