GWD5-Q3:

The average hourly wage of television assemblers in Vernland has long been significantly lower than that in neighboring Borodia.  Since Borodia dropped all tariffs on Vernlandian televisions three years ago, the number of televisions sold annually in Borodia has not changed.  However, recent statistics show a drop in the number of television assemblers in Borodia.  Therefore, updated trade statistics will probably indicate that the number of televisions Borodia imports annually from Vernland has increased.

 

Which of the following is an assumption on which the argument depends?

答案是：

C.    The average number of hours it takes a Borodian television assembler to assemble a television has not decreased significantly during the past three years.

求解释。另外 TELEVISION ASSEMBLER是啥意思？