The students were ________ over the ________ problem，listening to the teacher with a ________ expression on their faces.

We have dresses of various styles and patterns on sale and you may take ______ suits you best．

She bought the same skirt at a lower price at the same shop where I bought mine because she was a __________ customer.

Please remain _________ until the plane has come to a complete stop.

After reading the        school report, Tom really felt        .