关于英语倒装句和强调句　。　请帮我看下这两题怎么改。。

level 1

1.The students didn't stop talking until the teacher came in.
2.He didn't give up smoking until he got a serious disease.
将这两句改为倒装句和强调句拜托了！　

2012年09月27日 11点09分 1

level 1

Not until the teacher came in did the student stop talking.

2012年09月27日 12点09分 2

level 1

同理，第二句话也用这样顺序写

2012年09月27日 12点09分 5

level 1

Not until the teacher came in did the student stop talking.

2012年09月27日 12点09分 6

level 11

我试试~~~~~~ `
1.till the teacher came in did the students stop talking .
2.till he got a serious disease did he give up smoking .

2012年09月27日 12点09分 7

level 1

Not until the teacher came in did the student stop talking.

2012年09月27日 12点09分 8