岩石在载荷作用下发生变形，去掉载荷后变形不恢复，称作塑料变形。
参考答案：对
下图反映单位体积空气所能容纳的最大水汽量与气温的关系。
一定体积空气中含有的水汽量与同温度下这些空气所能容纳的最大水汽量的比值称为相对湿度。测得一封闭实验箱内的温度为30℃，相对湿度是50%，如果要使实验箱内的相对湿度降低到37.5%，箱内温度应调节为（）。
A．35℃
B．25℃
C．15℃
D．5℃
Directions:
You have just received a short message from your father informing that your mother is very ill and you want to ask for one week’s leave. Write a note (便笺) to your Office Head Mr. Wang about it.
You should write about 100 words on ANSWER SHEET 2.
Do not sign your own name at the end of the note. Use "Li Ming" instead.
Do not write the address.
