Mary is often heard ________ playing piano in the next room in the evening.

－prlfessor, do you have something       at this moment?－No,thanks.I'llcall you if there is any.

I didn’t do very well in the exam, and so I’m afraid of ___.

For breakfast he only drinks juice from fresh fruit _______ on his own farm.

____ the machine, the engineers paid much attention to the noise from it.