单项选择题
May I borrow your umbrella for a moment?（）
A.No, you can't do it B.Sorry, but you may not C.Well, I am afraid I am going to use it myself D.Of course not. I'm going to need it myself
单项选择题 May I ask you a question?（）
单项选择题 Mathematics（）study or science of numbers.
单项选择题 Mary told me that she（）to the supermarket before coming home
