Добрый день!
Помогите пожалуйста со следующим заданием:

Перепишите следующие предложения; подчеркните в каждом из них глагол сказуемое и определите его временную форму и залог:
1. Scientist have been looking for the substance as a source of energy for many years.
2. Becquerel`s discovery was followed by the intensive research work of Marie and Pierre Curie.
3. New methods of obtaining polymers have been applied at our plant.
4. The lecturer is listened to with great interest.
Заранее спасибо!!

1) have been looking - present perfect continues, active 2)was followed - past simple, yet passive 3)have been applied - present perfect continues , passive 4)is listened - present continues, passive