What's wrong with he?
① ____ A. summer B. winter C. season
② ____ A. which B. there C. why
③ ____ A. because B. pretty C. beautiful
如图,菱形ABCD中,AB=2,∠A=120°,点P,Q,K分别为线段BC,CD,BD上的任意一点,则PK+QK的最小值为( )