【正确答案】:
THERE IS POTENTIAL FOR INCREASING THE YIELD PER UNIT AREA ON THE EXISTING CULTIVATED LAND.
【题目解析】:there be句型,be动词的单数复数情况取决于后面所跟的名词的单复数。potential是单数,be动词用is。the yield per unit意为单位面积产量。
THERE IS POTENTIAL FOR INCREASING THE YIELD PER UNIT AREA ON THE EXISTING CULTIVATED LAND.