【单选题】Every possible means_____ been tried,and we find only______ this means can we do it well.
【简答题】在平面直角坐标系中,矩形纸片ABCD的长为4,宽为2.AB,AD边分别在x轴、y轴的正半轴上,点A与坐标原点重合.将矩形纸片沿直线折叠,使点A落在边CD上,记为点A',如图所示. (1)设A'的坐标是(2a,2)(0≤a≤2),写出折痕所在直线的方程; (2)若折痕经过B时,求折痕所在直线的斜率,并写出以折痕为直径的圆方程.
【单选题】We have to ______ everything question in detail ______ we take action. [ ]
B.
make analysis of; when
【单选题】— We haven't done very well ,have we ? — At least we tried . [ ]
【简答题】课堂上老师提出这样一个问题:你能用手中的矩形纸片尽可能大的折出一个菱形吗?有两位同学很快折出了各自不同的菱形,如下甲、乙两图: (1)如果该矩形纸片的长为8,宽为6,则甲、乙两图中的菱形周长分别为:____,____(直接写出答案) (2)这时老师说,这两位同学折出的菱形周长都不是最大的,聪明的你能够想出最大的菱形应该怎样折出来吗?如丙图所示:在矩形ABCD中,设AB=6,AD=8,请你在图中画出...
【单选题】We judge others around us easily, but have we ever tried to figure out our own personality?
【单选题】下列药材在采收加工时进行“发汗”的是()
【单选题】____ we have tried it, we can't imagine how hard it is. [ ]
【单选题】下列药材在采收加工时进行“发汗”的是 ( )