The four years, from 1860 to 1864 ___ Lincoln spent fighting for freedom of the slaves is the time ___ the American people will never forget.
Scientists ____ thousands of chemicals before they decided on the right one in the end.
The deserted island is only _______ by boat.
As is widely acknowledged, a great number of traffic accidents ____ numerous deaths and countless property loss all over the world every year.
To their great _____, Tom’s problem proved not to be as serious as they had feared.
________ we had read your letter _____the true state of affairs.