This medicine discovered by Tu Youyou ________ many people’s lives since it was put into use.

_______ more and more people speak the global languages of English,Chinese, Spanish, and Arabic, other languages are rapidly disappearing.

My father often encourage me _____

________ by his impressive performance, Peter will probably be accepted by a key university.[]

How much should I pay for the food, Sir— It costs ______. The food is free on our ship. ______ needs to pay for it.