It took us several hours to make the old man ________ of the safety of travelling by air.

Although at times learning to play the piano Was tiring for me，it was well worth he_______.

— Look, where are you going?— I can’t ________ the map and drive at the same time, can I?

The expert says that nowadays there are too many problems linked to poor diet and a ________of exercise.

Sadly the reading room where Karl Marx did a lot of reading had moved from its     place into another building.