Mary's grandpa is always ______ in the mountain village. He tells her he feels very______. So she's going to visit him next week.
A:alone; alone
B:lonely; lonely
C:lonely; alone
D:alone; lonely
如图,在△ABC中,∠C=90°,点E是AC上的点,且∠1=∠2,DE垂直平分AB,垂足是D,如果EC=3cm,则AE等于( )