Paper money was in ____ use in China when Marco Polo visited the country in ____ thirteenth century.
The most crowded part in a city is usually the city center, ______ many shopping malls and office buildings.
Although his present wasn’t worth too much, I still appreciated it very much. In my view, it’s the thought that ______.
Lucy: Mike seldom has breakfast at home, ______? Grace: _____ this morning.
The radio club in our school, which is in ___ charge of He Wei, is much more than just to play _____ music for everyone.
Walking on the street,___________.