Scientists say it may be five or six years _____ it is possible to test this medicine to human patients.
A．since B．after C．before D．when
At last we reached a lonely village, _______ a beautiful river.
A．in front of it lay B．in front of which lay
C．in front of it laid D．in front of which lied
It was the training ______ he had as a young man _____ made him such an excellent speaker.
A．which; which B．which; that C．that; which D．that; what
---Why did you leave that position?
---I a better position at IBM.
A．offer B．offered C．am offered D．was offered
--Have you got the leaving time of the train for me?
---Yes, but you’d better ____of it by yourself.
A．make sure B．be sure C．to make sure D．be certain
Jumping out of ______ airplane at ten thousand feet is quite ______ exciting experience.
A．/; an B．/; the C．an; an D．the; the
