平面的一条斜线和这个平面所成角θ的取值范围是______.
根据线面角的定义可得:斜线与平面所成角的取值范围是(0,π2).
故答案为:(0,π2).
— Let's go to the concert tonight, Michael!
— Sorry, I _____. I have to help my mother with the housework. [ ]
A. mustn't
B. may not
C. needn't
D. can't
假设在设计视图中创建一个查询,如图所示,试根据设计视图的内容,写出对应的SQL语句。