It’s necessary to have some____ knowledge for this job.

       He told me that she had met one of my old friends in the street ________.

Only by seizing every possible_____ to practice can you possibly hope to improve your spoken English.

If you don’t take away all your things from the desk, there won’t be enough_____ for my stationery.

It is a pity that none of the ______ stopped ______ the poor man lying there, begging.