When we use the -ing form of a verb as an adjective, we
mean that the person/animal/thing does the action of the
verb (e.g. an exciting book means "a book which excites
people").
When we use the past participle (the-ed form) of a verb
as an adjective, we mean that the person/animal/thing is
the object of the action of the verb (e.g. an excited child
means "a child whom someone or something has excited).
Choose the right words each time:
Mr Gray was (astonished/astonishing) to hear that there were two
hotels in such a small place. When he heard this
(astonished/astonishing) news, he was a little happier. His work
is (tired/tiring), and when he is very (tired/tiring), he often gets
ill. He finds talks about medicine on television very (inter-
ested/interesting). His wife is also (interested/interesting) in such
things, but last time they watched television, there were some
(annoyed annoying) flashes of light during the talk, and the
television company received a lot of telephone calls from
(annoyed/annoying) people.

Mr. Gray was astonished to hear that there were two hotels in such a small place. When he heard this astonishing news, he was a little happier. His work is tiring, and when he is very tired, he often gets ill. He finds talks about medicine on television very interesting. His wife is also interested in such things, but the last time they watched television, there were some annoying flashes of light during the talk, and the television company received a lot of telephone calls from annoyed people.