After two years' research, we now have a ______ better understanding of the distance.
A:very
B:fairly
C:far
D:quite
“旭日东升”是以 ____为参照物的,“日落西山”是以 ____为参照物的.
如图,在边长为2的菱形ABCD中, ∠ABC=120°, E,F分别为AD,CD上的动点,且AE+CF=2,则线段EF长的最小值是____.