Найдите в предложениях глаголы. Выпишите их и определите время в котором они употреблчются.  Нowever, naturalists have carried out some experiments to investigate such behaviour. The evidence suggests that pets seem to react to their owners' thoughts and intentions but the mechanism of such communication remains unknown. Аnother thing scientists are unable to explain is animals' sense of direction. How can pigeons find their way back home over hundreds of miles in unfamiliar places? The research into animal navigation has not helped to solve this mystery. In some experiments pigeons were taken away from home in closed vans to check whether they could remember their way. They were still able to find their way home easily. They could navigate on cloudy days and even at night which means they don't use the sun. And they couldn't smell their home because they were miles away from it.