13. By the end of last year we more than 2000 teachers of English all over the province .
I decide to ____ a more positive attitude after hearing the moving story of the disabled singer.
Mark said that he was unfit for the job, so he decided to _____ from the company.
—If not controlled, some terrible diseases will spread in the stricken areas after the terrible earthquake. —So people there are in _____ need of medical teams.
Foreign trade, the ____ of goods between nations, takes place for many reasons.
The famous professor’s lectures, though ____ informal, are considered far more informative and interesting.