8.【单选题】经济基础是指（）

There are always different kinds of ____ from this tour group.

What is the ____ of that flight attendant?

This airline has 150 international ____.

He has finally ____ in the new city.

What is the ____ of your visit to this city?

The reservation agent ____ a window seat fot him on the flight.

There is not even one ____ seat on this flight. It＇s all booked.

I have ____ from the cold and will go to work today.

The market has many products with heavy ____.

Where is the city ____ office?