单选题 After____ the numbers' in every possible combination, we finally hit on a solution.

单选题 His scientific discoveries have been as important as ______ of Sir Isaac Newton.

单选题 For my part, I have not the slightest doubt ______ he is an honest man.

单选题 Nelson became ______ of the Victory in 1800.

单选题 When I look at myself ______ the mirror, sometimes I get frightened.

单选题 The firm’s promise to increase our pay was a concession ______union demands.

单选题 He pulled a hat down ______his eyes and started walking along the avenue .

单选题 Nearly every time I picked up a newspaper, I found a reference ______ the use of industrial gases.

单选题 Gold has been highly prized throughout the ages due chiefly to ______.