根据短文内容及首字母提示，填入适当的单词，使短文的意思完整。（在填写答案时，单词的第一个字母要写出来）
Have you ever seen Korean writing before? In many people's eyes, it l____ lovely but difficult. Do you know the h____ of the special letters?
Long ago, Korean people didn't o____ their letters. At that time, they used Chinese characters(字符). Because Chinese is hard to learn, only rich people had the m____ and time to ask teachers to teach them. One of their kings was called Sejong. He decided to i____ Korean Letters. He thought hard.
One day, on O____ 9, 1446, he looked at a window frame(框架)and shouted, “I know what our letters should be!” He was so excited that he cried it loudly. He got the i____from the frame and invented letters of all the same size. It seemed that they were put in a window frame. The earliest Korean letters were born. King Sejong said, “Chinese characters can’t express Korean meanings. Now I invent o____ own letters. These letters are very e____ to learn. I hope that they can help all people learn to read.”
When King Sejong first invented the Korean letters, they had 28 letters, but only 24 are used today. All the Korean people enjoy u____ their own letters. Some Chinese young people think they're interesting.
2KCl+3O2↑，如图表示一定质量的KClO3和MnO2固体混合物受热过程中，某变量y随时间的变化趋势，纵坐标表示的是（ ）
