The professor was ________ to give us a lecture this afternoon, but it has been cancelled because of the delayed flight.

The lift in that tall building went wrong and got trapped ________ the floors. People in it had no way out and were in panic.

You needn't have apologized for your absence_______, it' s hardly your fault.

 I'm interested in a single room. Do you have any ________？

We have very strict quality control and anything imperfect is________，so customers feel secure about our products.