A:By studying with a group.
B:By asking his teacher questions.
C:By remembering all the words.
已知⊙O的半径为15,弦AB的长为18,点P在弦AB上且OP=13,则AP的长为( )
设全集U=R,集合M={x|0<x≤1},N={x|x≤0},则M∩(∁UN)=( )