材料的冲击、振动荷载作用下，产生较大变形，但不导致破坏的性质称为（）。
A.弹性
B.塑性
C.脆性
D.韧性
参考答案：B
In relation to the law of obligations:
(b) Explain the provisions of the Civil Code in respect of the late performance of civil obligations. (7 marks)
It happened to be very cold（）the morning of our sports meet.
A.at
B.of
C.on
