Professor Lee failed many times but he ________found a good way to solve the problem.

33. The employees have not been paid _______ since the new manager took over this company last month.

He looked at those jewels one after another ______and seemed to show no interest in any one of them.

Although China has developed its economy greatly, its per capital GDP is still         one-tenth of the United States.

It’s always difficult being in a foreign country, ___________if you can’t speak the language.