（１）I have just finished my homework.
（２）John has already read the book.
（３）He has lost his watch.
（４）I have seen the movie twice.
（５）Mary has met him before.
（６）I have lived in Japan for five years.
（７）Kiefer has known Carlos since 2017.
（８）Have you finished your homework? No, I haven’t.
（９）I haven’t finished my homework.
（10）I have just met John.
（11）Selena has already seen the movie.
（12）Mary has read the book three times.
（13）Have you washed your hands? Yes, I have.
（14）Jack has studied Japanese for two years.
（15）I have seen his brother many times.