英语问题（50分,回答好追加）

英语问题（50分,回答好追加）
1 This is the place where we played.这里的where为什么能换成to which?
2 I left the U.S for China.这句话是不是我离开了美国来到了中国?
3 on tiptoe是踮着脚,是不是可以这样说：“He is on tiptoe.?那作为动词是踮着脚,该怎么用?
4 The policeman talked to me over his shoulder.这句话为什么是：”那警察转过头跟我说话?”
5 There were over 500 students on the ground.这里的over能不能换成more than呢?
6 He is up to his knees.是什么意思?为什么说他跪坐着?
7 With all his wealth,he is not happy.这句话是即使拥有财富,他还是不快乐.即使不是even if吗?
8 with+名词是副词作用,能举个例子吗?
9What are you about now,为什么书上说是与what are you doing now同意思?
10with+宾语+形容词的附属语.怎么用?
万分感谢!

1.应该是换成at which吧 这里要理解成we played at the place
2.是 不过感觉那个the好别扭……
3.这个词组没听说过 不过有一个on one's toes动词就可以说stand on one's toes
4.over his shoulder意为越过自己肩膀 可以理解为回头 转头
5.可以
6.up to his knees是跪着的意思
7.对 但这里是意译
8.暂时没想起来-.-
9.不太清楚 应该是习惯用法吧
10.With his eyes closed,he talked to me.