问题
选择题
制作并观察洋葱内表皮和口腔上皮细胞的实验中，你观察细胞中染色最深的结构是（ ）
A．细胞壁
B．细胞膜
C．细胞质
D．细胞核
答案
答案：D
题目分析：细胞核是遗传信息库，细胞核中含有染色体，染色体是容易被碱性染料如碘液染成深色的物质，因此观察经过染色的洋葱鳞片叶表皮细胞和口腔上皮细胞时，各部分结构中染色最深的是细胞核，故选D。
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制作并观察洋葱内表皮和口腔上皮细胞的实验中，你观察细胞中染色最深的结构是（ ）
A．细胞壁
B．细胞膜
C．细胞质
D．细胞核
答案：D
题目分析：细胞核是遗传信息库，细胞核中含有染色体，染色体是容易被碱性染料如碘液染成深色的物质，因此观察经过染色的洋葱鳞片叶表皮细胞和口腔上皮细胞时，各部分结构中染色最深的是细胞核，故选D。
| Choose the best topic from A to F according to the meaning of each paragraph. | |
| International travelers, whether traveling for business or pleasure, will find themselves alone from time to time. Here are a few ways to meet new people and perhaps even get new travel chances. ( )1. Be polite and friendly. Remember to put yourself in social situations. Restaurants, shops and parks are all great places to meet people. If you want to make local friends in a country, stay near the places the locals often visit. ( )2. Keep a small photo album in your bag when you travel. Photos of family, friends and pets will help your new friends learn more about you. They will share their similar experiences with you, and it will help you learn more about your new friends. ( )3. Can you help your new friends improve their Chinese? Can you cook a traditional Chinese meal? By sharing your experiences, you can have a close relationship with your new friends that they won't soon forget. ( )4. Many foreigners love Chinese goods but have to pay a lot when buying them in their homeland, so you'd better prepare some gifts such as silks, tea and china (瓷器). They are always popular. ( )5. If you and your new friends get along well, you can give them your information and plan to live in each other's house for your next trip. Then you can visit their countries and stay in their houses while they stay in yours. In this way you will improve your friendship and live like a local abroad, but pay less for traveling. | |
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