The students were ____ over the ____ problem, listening to the teacher with a ____ expression on their faces.
I have little doubt about his competence; ______, he is well-qualified for the job.
We will ______ all the natural resources if we continue consuming them like that.
The village has developed a lot ________ we learned farming two years ago.
The kitchen is often the busiest room in a household, so it’s important to make sure it _____well.
______ label to each of the trees, with detailed introduction of their features, and visitors will know more about them and how to protect them.