a piece of 一块，一张，一片，不可数
a loaf of 一条
a bar of 一块
a bottle of 一瓶
a pound of 一磅
a quarter of 四分之一
a tin of 一罐，一盒
a carton of 一盒
a flock of 一群
make the tea
ask sb. （sth.）问某人（某事）
go and ask him go and ask him the way
ask sb. to do sth. 让某人做某事
Don't ask him to type the letter. ask him to go.
ask sb. for sth. 问某人要某物
A beggar asks him for money. You can ask him for help.
