81. Male and female students are quitedifferent from each other ______ the age at which they begin to develop anintellectual self-discipline.

You bought the car about ten years ago —Yes. ________it’s old, it still runs well.

The reason ______ he gave for not coming was ______ his mother wouldn’t allow him to.

_______ they _______ the book _______ to the library yet—Yes, they have.

Go and get your coat .It’s _____you left it .