When ambiguous sentences are put in a certain context, ambiguity disappears. Please fill in a sentence in the horizontal line below to eliminate the ambiguity of the sentence.

He told a joke intermittently and laughed at the same time, but it happened that the joke was very long and lasted for a long time …

He has a lot of jokes in his stomach every day, and he tells them to us whenever he has time. ...

His father has been a surgeon for many years, but he is still very nervous.

..... He was very nervous and hoped that his father's operation would be successful.