Grace doesn't like math because she thinks it is ________.
A:difficult
B:fun
C:useful
D:interesting
如图,三个小正方形的边长都为4,则图中阴影部分面积的和是____ .(结果保留π)
下列判断一定错误的是( )
设集合A={0,2,4,6,8,10},B={4,8},则∁AB=( )