He is good at ________ himself _______ new things,which makes me admired.

You can’t borrow books from the school library _______ you get your student card.

You can see that the young graduate is just of ______ height. [ ]

_____ boys and girls in that school are almost equal, of which both of the headmasters are proud. [ ]

We were told not to touch the equipment inthe laboratory unless ________.