—what do you think of Bill? —He is a hard-working student and he always ____himself in study.
----See? Only ten dollars for such a nice tie? ------OK,_____.
The teacher is much kinder to the top students, ______ makes the others unhappy.
Too much work and too little rest ____ to his illness.
Some experts demanded that children _______ time for sleep and play.
This type of jewelry is ______, so you’d better buy some as soon as possible.