Now that we have succeeded in isolating this drug, our next problem is to plan its in the laboratory.

单项选择题The President has again ______ with Congress over his budget plans.

单项选择题One reason for the success of Asian immigrants in the U.S. is that they have taken great ______ to educate their children.

单项选择题Key resources are technical personnel and aircraft spare parts which account for the largest share of the maintenance ______.

单项选择题Material choices such as timber and steel also help to keep the house cool, while light colours have been used on the exterior surfaces to ______ heat and blend in with the surrounds.

单项选择题A pair of night birds circled above, the ______ of their wings and their weird screams penetrating the thickening mist.

单项选择题The ______ among his sisters was that he ought to marry the girl as soon as possible to avoid a scandal.

单项选择题It is unlikely that enough qualified teachers will be found unless there is ______ improvement in salaries and conditions of housing.

单项选择题They aim to ______ the maximum economic benefit from the Olympic Games.

单项选择题It is hoped that the prisoner will be released through the ______ of the president himself.

单项选择题Recent changes in climate may ______ that global warming is starting to have an effect.