单项选择题 The National Institute of Health is discussing ways of tackling the problem of childhood（）.

单项选择题 To （）how the system works，Bruce shows off the prototype of a 3D analysis tool.

单项选择题 We’re firmly（）to the manager’s latest decision to expand overseas market.

单项选择题 Mozart had an incredible capacity to（）other individuals，their facial gestures，their dialects.

单项选择题 Citric acid can be （）from the juice of oranges，lemons，limes or grapefruit.