【正文】
How to use: You __________ the metal band over your head,__________ your mind,_________ the button and instantly it’s __________. Advantages: It’s quick, ___________ and ________________ friendly. Disadvantages:The only ___________is that the user should think his or her message clearly. place clear press sent efficient environmentally limitation Waste machine: What it is like: It is a big machine, which is always _________ for more, _________ all the waste. Advantages: It turns the _________into useful things. ________is wasted, and everything, even plastic bags, is ________. greedy swallows rubbish Nothing recycled Robots: How it is used: The robots are programmed to perform _______ in space, and produce _______ which are shipped back to earth. Advantages: There is no _______, no _________,no ______________ damage! Disadvantages: People have to _____ and work in the space station and __________ the robots and the production. tasks goods waste pollution environ