_________ beautiful natural scenery of Ireland attracts millions of tourists every year and tourism is now _________ big industry.
It's impossible________back the wheel of history.
The bell________the end of the period rang, ________our heated discussion.
The policeman said the accident last night______careless driving, so much money________be paid by the driver.
The matter________your study surely requires________carefully.
When they came to a new country, they found it difficult to________themselves to new circumstances.