用所给词的适当形式填空。 1. The children are singing and dancing ____(happy) on the playground. 2. We enjoyed _________( oneself) in the park last Sunday. 3. The workers ________ ( produce) a new kind of machine. 4. But I _______ ( real) cannot go to town with you tomorrow. 5. I'm ______( especial) busy this morning. What about this afternoon? 6. Throw it away. It's quite _________( worth) . 7. Could you give me some _________( advice) on this problem?