一、注重“知识陷阱”的设置与利用,加深对概念理解合理的设置“知识陷阱”,并充分地加以利用,是巩固、理解概念的一个好方法。例1.已知m、l是直线,α、β是平面,给出下列命题: ①若l垂直于α内的两条相交直线,则l上α; ②若l平行于α,则l平行于α内的所有直线; ③若m α,l β且l⊥m,则α⊥β; ④若l β,且l⊥α,则α⊥β; ⑤若m α,l β且α∥β,则m⊥l. 其中正确的命题的序号是:____ 简析:①符合线面垂直判定定理; ②故意与线面垂直的性质定理(若l垂直于α,则 I. Focusing on the establishment and use of the “knowledge trap” and deepening the reasonable “knowledge trapping” of conceptual understanding, and making full use of it, is a good way to consolidate and understand concepts. Example 1. Know that m, l is a straight line, α, β is a plane, given the following proposition: 1 If l is perpendicular to the two intersecting lines in α, then l on α; 2 if l is parallel to α, then l parallel All lines within α; 3 if m α,l β and l⊥m, then α⊥β; 4 if l β, and l⊥α, then α⊥β; 5 if m α,l β and α∥β , then m⊥l. where the serial number of the correct proposition is: _____________________________________________________________________________________________________________________________________