【判断题】Read the following question and introduction below. Some people believe the arts should
not be taught in schools as subjects such as computer skills and
accounting are more important in the modern w...
【单选题】导热传递的热量与 成正比。 I.表面温差;II.垂直热流的截面积;III.厚度;IV.导热系数。
【简答题】In all modern school systems the textbook has long served not only to support instruction but to symbolise that instruction, in other words, the textbook defines the ( ).
【单选题】关于铸造,下列说法错误的是( )。
A.
铸造可以生产出形状复杂,特别是具有复杂外腔的工件毛坯。
B.
产品的适应性广,工艺灵活性大,工业上常用的金属材料均可用来进行铸造,铸件的质量可由几克到几百吨。
C.
原材料大多来源广泛,价格低廉,并可直接利用废机件,故铸件成本较低。
D.
铸件组织疏松,晶粒粗大,内部易产生缩孔、缩松、气孔等缺陷。
【简答题】阅读理解。 All the cities are quite the same. Living in a modern Australian city is not very different from living in an American city. But there are some differences on farms. In many parts of the world, ...
【单选题】古代有“八音”,即金、石、丝、木、土、革、匏(páo)、竹,其中“金”是指什么材质的乐器?
【单选题】能将矩形波输入信号转换成三角波输出信号的电路为( )。