单项选择题 The companies that are finding ways to hang on to their older workers（）from an intangible commodity: wisdom.

单项选择题 Speakers and writers of the Germanic languages（）for a great deal of the world's output in everything from economics to literature to military to science and technology.

单项选择题 We know that many animals（）the deep seas at pressures of 15,000 pounds per square inch.