Within industries，companies are always trying to develop products that are one step better than _____ of other companies．

--How many people were there at the meeting?-- _______. All the people went on a trip to Beijing.

 ________ is known to us all that the sun rises in the east.

Suddenly I met a friend of ___ and we said hello to each other .

 I'm moving to the countryside because the air there is much fresher than _______ in the city.