用单词的适当形式填空 1. Look, the children are doing morning _____________ (exercise). 2. My brother and I like ___________(drink) coffee. 3. The bird can _______________ (sing) the “ABC” song. It’s very clever. 4. His mother often___________ (help) him to do his homework. 5. There are many________________ (different) between you and your twin brother.