未知题型
Paper is one of the most important products ever invented by man.英译汉
纸张是人类发明的最重要的产品之一。
未知题型 Semiconductor chips are small in size and light in weight.英译汉
未知题型 工程材料按所起的作用分类有:
未知题型 A ir pollution is more serious than water pollution.英译汉
