I will visit Austria ______ the invitation of my friend this summer vacation．
A．by B．for C．to D．at
—Is there any mail?
—No, ______ at all．
A．nothing B．none C．no one D．neither
Programmes, ______ to bring the old and the young together, are growing in popularity all over the world．
A．designed B．to be designed
C．designing D．having designed
David _____ a customer when the fire started．
A．served B．was serving C．had served D．would serve
Martin drove along ______ he found a convenient parking place．
A．after B．when C．until D．since
—Excuse me, visiting hours are over．It' s time for you to leave．
—I' m sorry, I didn't know the time or I ______ earlier．
A．will leave B．would leave
C．had left D．would have left
