The girl looked at me with a ____expression. Maybe the problem was quite ___.

It has been announced that candidates ( 候选人)_____remain in their seats until all the papers has been collected .

Many of the things we now benefit from would not be around _______ Thomas Edison.

I like getting up very early in summer. The morning air is sogood________．[ ]

The students are _______ to ride the public bicycles to Mount Tianlong for a spring outing.