送电施工中常采用的钢丝绳为()。
A、顺绕;
B、交绕;
C、单绕;
D、没有要求。
参考答案:B
---Does China have cultural relics?
--- Yes, it is admitted that many cultural relics in the world, such as the Great Wall, the Potala Palace, the Magao Caves and so on, ______ China.
A.belongs to
B.are belonging to
C.belonged to
D.belong to
摩擦学研究的对象很广泛,概括说研究摩擦、磨损(包括材料转移)和润滑(包括固体润滑)的原理及其应用。概括起来有哪八个方面?