In the environment area, there is a system ________ the waste is disposed of by using the principles of ecology.
–Can I _________, sir?---Yes, please. Two dinks.
So far the young man hasn’t had any success; ______ he will keep trying.
–Excuse me, Madame. Is this plane _____take off soon?---Oh, yes. In five minutes.
_____for his expert advice, he was able to help a great number of people with their personal affairs.
As soon as the manager enterd his office, he began to ______the telephone.A.look up B. look upon C. look through D look for