1.等待我的轮次做某事是wait for my turn to do sth 还是wait for my turn on

1.等待我的轮次做某事是wait for my turn to do sth 还是wait for my turn on sth 还是wait for my turn on doing sth
2.size是名词,课文上问What's your size?,下面却回答I'm a size eight 为什么不说My size's eight
3.What's your size?的同义句有哪些?
4.课文中开头说I'd like to buy a pair of football boots 这里有a pair of ,所以不是应该做单数讲的吗?下文怎么说Could I try then on