【单选题】A. A professor. C. A designer. B. A manager. D. An engineer.
【单选题】Which of the following statement about the Burgers vector is incorrect.
A.
它的大小表征了位错的单位滑移距离,方向与滑移方向一致。
B.
伯氏矢量的大小决定了晶体中何处易出现形成位错以及在外力作用下位错运动的难易程度。
D.
混合位错 的伯氏矢量既不平行也不垂直于位错线,故混合位错由刃型位错与螺旋位错叠加而成。
【简答题】19-21 Now you'll hear the two long conversations. Conversation One 19. A. She feels embarrassed when speaking in public. B. Her presentation receives a poor grade. C. She has not completed her assignm...
【简答题】听第 10 段材料,回答第 17 至 20 题。 17. What is the speaker? A . A freshman in Deep Springs College. B . An editor in the college. C . A professor in the college. 18 . What is L . L.Nunn's intention to found Dee...