The three of us ______ around Europe for about a month last summer.
A．traveled B．have traveled C．had traveled D．travel
Experiments of this kind _______in both the U.S. and Europe well before the Second World War started.
A．have conducted B．have been conducted
C．had conducted D．had been conducted
Robert is said________ abroad, but I don’t know what country he studied in.
A．to have studied B．to study
C．to be studying D．to be studied
We live in an age ________ more information is available with greater ease than ever before.
A．why B．when C．to whom D．on which
Tom took a taxi to the airport, only _____ his plane high up in the sky.
A．finding B．to find C．being found D．to have found
The market competition is fierce, but our products have great advantage ______ quality and price.
A．in place of B．in view of C．in case of D．in terms of
