单项选择题
A．now and then B．over and over C．up and down D．here and there
A．stored up by the plants B．absorbed by the earth’ s atmosphere C．stored up by the animals in the form of body fat D．used for electric power
A．universities in the UK have produced too much good for graduates B．such abstract subjects as philosophy is no longer useful C．education should serve the social needs D．it is advisable for today’ s philosophers to know computer science