Operation rooms should be kept free ______ bacteria of any kind.
Some people often take __________ for granted __________ what is new is always better than what is old.
The audience was __________ very young children.
Pressure applied __________ the wound will stop the bleeding.
—Where was it __________ the road accident happened yesterday?—In front of the market.
It was on National Day __________ I visited Shanghai Expo.