The best way of learning a language is using it. The best way of learning English is talking in English as much as possible. Sometimes you'll get your words mixed up(混合) and people will not understand you. Sometimes people will say things too quickly and you can' t understand them. But if you keep your sense of humor(幽默感)，you can always have a good laugh at the mistakes you make. Don't be unhappy if people seem to be laughing at your mistakes. It's better for people to laugh at your mistakes than to be angry with you，because they don't understand what you are saying. The most important thing for learning English is："Don't be afraid of making mistakes because everyone makes mistakes."

唐太宗时期把公主嫁给松赞干布，大大促进了_______经济文化的发展与进步（    ）

人类在探索自然规律的过程中，总结出了许多科学研究方法．下面的几个研究实例中，与研究磁场时引入“磁感线”所用方法相同的是（　　）