金属材料的塑性是金属材料在载荷作用下，产生变形不破坏的能力。（）
参考答案：对
— Several department stores, including the one we usually go to, ____ sidewalk sales this week
— Let's go and have a look.[ ]
A. is having
B. are having
C. has
D. have had
下列防晒行为不正确的是（）。
A.涂抹一些防晒霜
B.向皮肤洒水
C.使用太阳伞
D.晒后使用涂抹一些清凉油
