The work was difficult, but Tom’s ____expression showed that he would finish it in time.

Don’t be too ________ about things you are not supposed to know．

All of the students were ______ by the ______speech given by the     headmaster.

When he came back, his wife was found _________.

If you are going to stay in the United States for longer than a(n) ______ visit, you may be interested in learning more about its people and culture.