Attempts to explain the pattern of international trade
A: have been a major focus of international economists.
B: have proven to be hopeless.
C: have proven to be a trivial exercise.
D: have been the preoccupation of economic development theorists.
A: have been a major focus of international economists.
B: have proven to be hopeless.
C: have proven to be a trivial exercise.
D: have been the preoccupation of economic development theorists.
举一反三
- French is one of the major languages_____at international conferences. A: to use B: to have used C: used D: to have been used
- 3. People who exercise often are proven to have stronger __________ systems.
- Which of the following policies have never been implemented?（ ） A: Minimum purchase price B: Centralized trade C: Use international prices D: Target price
- It’s a shame _________ able to give them any advice. A: not to have been B: to have not been C: to have been not D: to not have been
- 中国大学MOOC: The universities in the United States have been attracting ______ number of international students.