If he were the president, he would provide better for us.
If my boss should call, please take a message.
If airport security had known about the dangers, they would have secured the airport better.
If they had not secured the airport properly, something terrible would have happened.
Did Christopher Columbus discover America in 1492 or in 1592? АЛЬТЕРНАТИВНЫЙ Christopher Columbus discovered America in 1492, didn't he? РАЗДЕЛИТЕЛЬНЫЙ
Who discovered America in 1492? К ПОДЛЕЖАЩЕМУ
When did Christopher Columbus discover America? СПЕЦИАЛЬНЫЙ
2) Was he born in Italy but lived in Spain for a long time?
Was he born in Italy or in France? Did he live in Spain or in Italy for a long time?
He was born in Italy, wasn't he? He lived in Spain for a long time, didn't he?
Who was born in Italy but lived in Spain for a long time?
Where was he born? Where did he live for a long time?
3) Did he discover some more islands in Central America?
Did he discover some more islands in Central or South America?
He discovered some more islands in Central America, didn't he?
Who discovered some more islands in Central America?
Where did he discover some more islands? What did he discover in Central America?