_______ medical issues, we also have to face moral and legal issues when cloning human beings.
I found them ______ at a table, _______ in thought.
In class, the students are __________ in the teacher’s words.
When she heard the strange news, a ____ look _____ on her face.
The reasonhe made such kind of mistakes is that he has had no _______ experience of this kind of job.
His health _____ under the too much pressure of work.