1.It‘s a great honour to be invited to Mary’s birthday party.（不定式作主语）
2. He went to the hospital to be examined.（不定式作状语）
3. There are still many things to take care of.(不定式作定语I have things to take care of.)
4. There are still many things to be taken care of. (不定式作定语I have things taken care of.)
5.He seems to know where the hidden book is. .(动词不定式的现在时)
