It's kind_________ you to help organize our Helping Hands Meeting because it's still difficult _________ the children in poor areas to go to school.
A:for; of
B:for; for
C:of; of
D:of; for
在平面直角坐标系中,已知直线y=- 34 x+3与x轴、y轴分别交于A、B两点,点C(0,n)是y轴上一点,把坐标平面沿直线AC折叠,使点B刚好落在x轴上,则点C的坐标是( )
从某种产品中抽取400件检测其质量,检测结果为:一等品80件,二等品185件,三等品115件,其他为次品,则由此估计在此产品中,买一件产品为次品的概率为()
碳及其化合物是初中重要的化学物质.
— I think it's Mr. Zhang.
如图中D是BC的中点,E是AC的中点,三角形ABC的面积是三角形DEC面积的( )倍.