There_____ be any difficulty in passing the road test since you have practised a lot in the driving school. A. mustn't B. shan't C. shouldn't D. needn't 答案:C下面有关新材料的说法正确的是( )A.超导体、半导体、纳米材料等新材料的开发和利用,正在日益改变着我们的生活方式B.常见的半导体材料有铜、硅、锗、砷化镓等C.纳米材料是一种新材料制成的大米D.超导体是一种电阻为零的材料,可以用来制造灯丝,灯泡会特别亮