Be sure to read the ________ before you take the medicine.
Apples are usually sold by ______weight, and eggs are sometimes sold by ______ dozen.
Susan, ______ university student from Europe, teaches me ______ art in her spare time.
These young people are now making an active ______ to beautify our city.
--- My son is lost. Did you see a boy pass by here? --- I saw ______ boy hidden behind ______ tree over there. You may go and have a look.
The need for an operation,especially an immediate operation, almost always comes as a ______ to the patient and his family.