按要求改写句子。
1. Throw the football to him. (改否定句)
___________ throw ___________ the football.
2. No smoking! (改同义句)
It ___________ we ___________ ___________ here.
3. I'd like a yo-yo as my birthday present. (改一般疑问句)
___________ you like a yo-yo as ___________ birthday present?
4. He is flying kites in the park now. (改一般过去时)
He ___________ ___________ in the park just now.
5. The man drank a cup of tea here a moment ago. (否定句)
The man ___________ ___________ a cup of tea here a moment ago.
6. My mother goes to work on foot every day. (对画线部分提问)
___________ ___________ your mother ___________ to work every day?
7. He went to the cinema on Saturday evening. (对画线部分提问)
___________ ___________ he ___________ on Saturday evening?
8. They plant trees on the farm. (改过去进行时)
They ___________ ___________ trees on the farm.
9. My brother got two presents last Christmas. (改现在完成时)
My brother ___________ got two presents since last Christmas.
，Ⅱ度深覆盖，下切牙咬在上牙腭侧龈组织，上下前牙有散在间隙，面中1／3轻度前突，面下1／3较短。
，缩短治疗时间的机制是（）