Ребят, помогите, пожалуйста! Спасибо заранее!!
Поставьте глагол в Future Perfect.
1) The scientists think that they (to prove) their conclusion by the end of their experiments.
2) I think that I (to accomplish) my investigation by the beginning of the next year.
3) The researcher (to isolate) the necessary substance before he begins a new experiment.
4) Do you think we (to complete) our observations by the next month?