In the future, the world’s cooks may be using wooden knives. This may seem a little strange, but scientists have c【小题1】 a wooden knife. It is three times sharper than the steel knives we use. The scientists are from the University of Maryland. Researcher Teng Li said wooden knives would add to the n【小题2】 of wooden tools we use in kitchens across the world. He said, “In our kitchen, we have many wooden things that we use for a very long time, like a cutting board, c【小题3】, or a rolling pin (擀面杖). These new knives can also be used many t【小题4】 if they are polished and sharpened.”

The scientists improved the strength of their wood by i【小题5】 the cellulose (纤维素) it has. Cellulose is the m【小题6】 constituent (成分) of wood. It has a higher strength than steel and ceramics. The new material is so s【小题7】 that it can easily cut through the hardest steak. Another advantage of wooden knives is that they are environmentally f【小题8】. They could help us avoid using plastic cutlery (刀具). The scientists have also d【小题9】 wooden nails (钉子). These could help the building industry b【小题10】 they will not rust (生锈) like many nails.

Robots were invented to service human beings. They do some dull and d【小题1】 work instead of humans. Because robots will never get b【小题2】 and they are not afraid of danger. For example，a few years later，robots will go to a war，no m【小题3】 human. It can even be designed as an advanced（先进的）killing weapon. A【小题4】 there are a great part of the work will be replaced by a robot，what a robot does is only running its master's p【小题5】 .

Robots are s【小题6】 with human beings，but just in appearance. They may have similar s【小题7】 ，but they are quite different in nature. Because robots can not t【小题8】 and they have no emotion（情感）.Think about you are a doctor，you can think how to cure，use which kind of m【小题9】 .What a robot does is just some rigid tips，So they will never take the place of human d【小题10】 .