A: Have some juice.
B: ___________()
A:Thank you!
B:I’d like bread.
解方程:4x2﹣8x+1=0.
实验室有A、B两种溶液,A能使紫色石蕊溶液变红色,B能使无色酚酞溶液变红色,则A、B两种溶液的pH大小关系是A____B(填“大于”或“小于”).要测定A、B溶液的酸碱度,其做法是____.
(Ⅰ)已知点F在BC上,且CF=2FB,求证:平面PEF⊥平面PAC;
(Ⅱ)若△PBC的面积是梯形ABCD面积的 43 ,求点E到平面PBC的距离.
Do you brush your after up?
-92=____