The development of industry has been ________ gradual process throughout ________human existence,from stone tools to modern technology.
There is only one day left for us in Hangzhou and we will have a ________ tour around the city.
It was in the hotel ________ the famous singer lived _______ she was killed.
He worked day and night, and finally his dream ________ a teacher ________.
We have every reason to believe that ________ 2010 Shanghai World Expo will be ________ success.
— Manager, I’d like to take a week’s holiday.— ________. We’re too busy nowadays, you know.