对画线部分提问 ①That is Helen’s sweater.②The dog is under the bed.③Mike can sing the song.

对画线部分提问 ①That is Helen’s sweater.②The dog is under the bed.③Mike can sing the song.
画线部分分别是：
①Helen’s
②under the bed
③sing the song
给的句子是：
①_____ _____ is that?
②_____ _____ the dog?
③_____can Mike _____?