Complete the sentences using the past simple or present perfect.
1) the scientist ... his article. (to write / already).
2)andrew's hamster ... his food. ( to eat / just).
3) the boys ... an old cage in their garden. (to find / yesterday).
4)they ... the problem. (not / discuss / yet).
5) charles ... his translation. (to finish / just).

1 has already written2 has just eaten 3 found 4 They have not discuss the problem yet 5 has just finished