根据句意及首字母或汉语提示完成单词。 1. There are so many things here that I can't decide which one to c _____. 2. My English teacher often e _____ us to study English hard. 3. Study hard, and you will make _____ (进步). 4. This is Ann's _____ (私人的) letter, please give it to her. 5. Today is a _____ (特殊的) day in the history of our country.