一、单词拼写。
结合语境，根据汉语提示用单词的适当形式填空。
1．Her name is well known in ________ (学术) circles.
2．Now that you are able to take up arms and defend your ______ (祖国), we are all proud of you.
3．I did a lot of work on that book. It annoys me that the editor never ________ (承认) it.
4．Professor Blair is giving a series of ________ (演讲) on Einstein's theories.
