They usually have the medicine_______ before putting into the market all over the country.
Few people paid full attention to their health conditions __________ they were seriously ill.
The Chinese agricultural tax wasn't completely abolished __________2006,which reduced the farmers' burden greatly.
He complained __________ me __________ the food I had prepared.
You should try to be patient, Tracy. Learning a language is a slow __________. It takes time, you know.
The little boy looked __________ at the __________ tiger.