A. I haven't finished my homework yet.
b. I have already done my homework.
c. I have just finished my homework.
d. He has already gone home.
e. Mark has just come back from France.
f. They have just bought a new house.
g. We haven't had lunch yet.
h. The train has already left the station.
i. Has the train left yet(не уверена насчёт последнего)