Перепишите предложени, подчеркните сказуемое главного предложение и определите виде-временную форму и залог глагола.
(Например, was going - past continuous Active от глагола to go )
1 . Botanical prospecting has been used in the search for deposits of ores.
2. Men have been curious about the mysterious underwater world for centuries.
3. Scientists began serious research in this field only in our time