单项选择题
A．They are unable to be broken down into harmless products. B．They consume a lot of natural resources. C．They produce harmful gases. D．They are capable of being reused.
A．Positive. B．Indifferent. C．Cautious. D．Suspicious.
A．The society should ensure the poor have access to the technology. B．The society should ban the use of e-books if they cannot reduce eye fatigue. C．The society should approve of the use of e-books if they are made recyclable. D．The schools should solve the present problems of e-books.