. Going out for tea with friends increasingly popular during the past twenty years.
| A．becomes | B．became | C．has become | D．had become |
Key: C
We have already said a good deal about the various problems _______ the war.
| A．trying out | B．dating back to | C．appealing to | D．relating to |
Theory is ______ in that it can provide a direction for practice.
| A．valuable | B．typical | C．religious | D．narrow |
The boy then led her into the warm hall and left her ______ by the fire.
| A．sit | B．to sit | C．sitting | D．sat |
Between the two mountains _________ the factory where my father used to work.
| A．stand | B．standing | C．to stand | D．stands |
They were lost at sea, _______ the mercy of wind and weather.
| A．on | B．at | C．in | D．by |