I asked him how much ________________.
From what she has done we can predict that she is ______enough to make up her own decision and behave in a proper way.
Never______ such a difficult problem. It took me almost half an hour to work it out.
— Do you remember the first time we met? —At that time you ______us a lecture.
Your _______ as a student will be excellent if you develop a habit of reflecting on how you learn.
The scientists are beating their brains, trying to ______ a solution to the problem.