解救—____ 逐渐—____ 奇怪—____
愚蠢—____ 凶残—____ 狡猾—____
若倾斜角为π4的直线l通过抛物线y2=4x的焦点且与抛物线相交于M,N两点,则线段MN的长为( )
A.metal glass wool cotton wood
B.earth sheep trees sand plant